blob: 6875eb4a59fcc140a9aee1c9abef5e3859171351 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Security plug functions
*
* Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
* Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
* Copyright (C) 2016 Mellanox Technologies
* Copyright (C) 2023 Microsoft Corporation <paul@paul-moore.com>
*/
#define pr_fmt(fmt) "LSM: " fmt
#include <linux/bpf.h>
#include <linux/capability.h>
#include <linux/dcache.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kernel_read_file.h>
#include <linux/lsm_hooks.h>
#include <linux/fsnotify.h>
#include <linux/mman.h>
#include <linux/mount.h>
#include <linux/personality.h>
#include <linux/backing-dev.h>
#include <linux/string.h>
#include <linux/xattr.h>
#include <linux/msg.h>
#include <linux/overflow.h>
#include <linux/perf_event.h>
#include <linux/fs.h>
#include <net/flow.h>
#include <net/sock.h>
#define SECURITY_HOOK_ACTIVE_KEY(HOOK, IDX) security_hook_active_##HOOK##_##IDX
/*
* Identifier for the LSM static calls.
* HOOK is an LSM hook as defined in linux/lsm_hookdefs.h
* IDX is the index of the static call. 0 <= NUM < MAX_LSM_COUNT
*/
#define LSM_STATIC_CALL(HOOK, IDX) lsm_static_call_##HOOK##_##IDX
/*
* Call the macro M for each LSM hook MAX_LSM_COUNT times.
*/
#define LSM_LOOP_UNROLL(M, ...) \
do { \
UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__) \
} while (0)
#define LSM_DEFINE_UNROLL(M, ...) UNROLL(MAX_LSM_COUNT, M, __VA_ARGS__)
/*
* These are descriptions of the reasons that can be passed to the
* security_locked_down() LSM hook. Placing this array here allows
* all security modules to use the same descriptions for auditing
* purposes.
*/
const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = {
[LOCKDOWN_NONE] = "none",
[LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading",
[LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port",
[LOCKDOWN_EFI_TEST] = "/dev/efi_test access",
[LOCKDOWN_KEXEC] = "kexec of unsigned images",
[LOCKDOWN_HIBERNATION] = "hibernation",
[LOCKDOWN_PCI_ACCESS] = "direct PCI access",
[LOCKDOWN_IOPORT] = "raw io port access",
[LOCKDOWN_MSR] = "raw MSR access",
[LOCKDOWN_ACPI_TABLES] = "modifying ACPI tables",
[LOCKDOWN_DEVICE_TREE] = "modifying device tree contents",
[LOCKDOWN_PCMCIA_CIS] = "direct PCMCIA CIS storage",
[LOCKDOWN_TIOCSSERIAL] = "reconfiguration of serial port IO",
[LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters",
[LOCKDOWN_MMIOTRACE] = "unsafe mmio",
[LOCKDOWN_DEBUGFS] = "debugfs access",
[LOCKDOWN_XMON_WR] = "xmon write access",
[LOCKDOWN_BPF_WRITE_USER] = "use of bpf to write user RAM",
[LOCKDOWN_DBG_WRITE_KERNEL] = "use of kgdb/kdb to write kernel RAM",
[LOCKDOWN_RTAS_ERROR_INJECTION] = "RTAS error injection",
[LOCKDOWN_INTEGRITY_MAX] = "integrity",
[LOCKDOWN_KCORE] = "/proc/kcore access",
[LOCKDOWN_KPROBES] = "use of kprobes",
[LOCKDOWN_BPF_READ_KERNEL] = "use of bpf to read kernel RAM",
[LOCKDOWN_DBG_READ_KERNEL] = "use of kgdb/kdb to read kernel RAM",
[LOCKDOWN_PERF] = "unsafe use of perf",
[LOCKDOWN_TRACEFS] = "use of tracefs",
[LOCKDOWN_XMON_RW] = "xmon read and write access",
[LOCKDOWN_XFRM_SECRET] = "xfrm SA secret",
[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
};
static BLOCKING_NOTIFIER_HEAD(blocking_lsm_notifier_chain);
static struct kmem_cache *lsm_file_cache;
static struct kmem_cache *lsm_inode_cache;
char *lsm_names;
static struct lsm_blob_sizes blob_sizes __ro_after_init;
/* Boot-time LSM user choice */
static __initdata const char *chosen_lsm_order;
static __initdata const char *chosen_major_lsm;
static __initconst const char *const builtin_lsm_order = CONFIG_LSM;
/* Ordered list of LSMs to initialize. */
static __initdata struct lsm_info *ordered_lsms[MAX_LSM_COUNT + 1];
static __initdata struct lsm_info *exclusive;
#ifdef CONFIG_HAVE_STATIC_CALL
#define LSM_HOOK_TRAMP(NAME, NUM) \
&STATIC_CALL_TRAMP(LSM_STATIC_CALL(NAME, NUM))
#else
#define LSM_HOOK_TRAMP(NAME, NUM) NULL
#endif
/*
* Define static calls and static keys for each LSM hook.
*/
#define DEFINE_LSM_STATIC_CALL(NUM, NAME, RET, ...) \
DEFINE_STATIC_CALL_NULL(LSM_STATIC_CALL(NAME, NUM), \
*((RET(*)(__VA_ARGS__))NULL)); \
DEFINE_STATIC_KEY_FALSE(SECURITY_HOOK_ACTIVE_KEY(NAME, NUM));
#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
LSM_DEFINE_UNROLL(DEFINE_LSM_STATIC_CALL, NAME, RET, __VA_ARGS__)
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
#undef DEFINE_LSM_STATIC_CALL
/*
* Initialise a table of static calls for each LSM hook.
* DEFINE_STATIC_CALL_NULL invocation above generates a key (STATIC_CALL_KEY)
* and a trampoline (STATIC_CALL_TRAMP) which are used to call
* __static_call_update when updating the static call.
*
* The static calls table is used by early LSMs, some architectures can fault on
* unaligned accesses and the fault handling code may not be ready by then.
* Thus, the static calls table should be aligned to avoid any unhandled faults
* in early init.
*/
struct lsm_static_calls_table
static_calls_table __ro_after_init __aligned(sizeof(u64)) = {
#define INIT_LSM_STATIC_CALL(NUM, NAME) \
(struct lsm_static_call) { \
.key = &STATIC_CALL_KEY(LSM_STATIC_CALL(NAME, NUM)), \
.trampoline = LSM_HOOK_TRAMP(NAME, NUM), \
.active = &SECURITY_HOOK_ACTIVE_KEY(NAME, NUM), \
},
#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
.NAME = { \
LSM_DEFINE_UNROLL(INIT_LSM_STATIC_CALL, NAME) \
},
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
#undef INIT_LSM_STATIC_CALL
};
static __initdata bool debug;
#define init_debug(...) \
do { \
if (debug) \
pr_info(__VA_ARGS__); \
} while (0)
static bool __init is_enabled(struct lsm_info *lsm)
{
if (!lsm->enabled)
return false;
return *lsm->enabled;
}
/* Mark an LSM's enabled flag. */
static int lsm_enabled_true __initdata = 1;
static int lsm_enabled_false __initdata = 0;
static void __init set_enabled(struct lsm_info *lsm, bool enabled)
{
/*
* When an LSM hasn't configured an enable variable, we can use
* a hard-coded location for storing the default enabled state.
*/
if (!lsm->enabled) {
if (enabled)
lsm->enabled = &lsm_enabled_true;
else
lsm->enabled = &lsm_enabled_false;
} else if (lsm->enabled == &lsm_enabled_true) {
if (!enabled)
lsm->enabled = &lsm_enabled_false;
} else if (lsm->enabled == &lsm_enabled_false) {
if (enabled)
lsm->enabled = &lsm_enabled_true;
} else {
*lsm->enabled = enabled;
}
}
/* Is an LSM already listed in the ordered LSMs list? */
static bool __init exists_ordered_lsm(struct lsm_info *lsm)
{
struct lsm_info **check;
for (check = ordered_lsms; *check; check++)
if (*check == lsm)
return true;
return false;
}
/* Append an LSM to the list of ordered LSMs to initialize. */
static int last_lsm __initdata;
static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
{
/* Ignore duplicate selections. */
if (exists_ordered_lsm(lsm))
return;
if (WARN(last_lsm == MAX_LSM_COUNT, "%s: out of LSM static calls!?\n", from))
return;
/* Enable this LSM, if it is not already set. */
if (!lsm->enabled)
lsm->enabled = &lsm_enabled_true;
ordered_lsms[last_lsm++] = lsm;
init_debug("%s ordered: %s (%s)\n", from, lsm->name,
is_enabled(lsm) ? "enabled" : "disabled");
}
/* Is an LSM allowed to be initialized? */
static bool __init lsm_allowed(struct lsm_info *lsm)
{
/* Skip if the LSM is disabled. */
if (!is_enabled(lsm))
return false;
/* Not allowed if another exclusive LSM already initialized. */
if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && exclusive) {
init_debug("exclusive disabled: %s\n", lsm->name);
return false;
}
return true;
}
static void __init lsm_set_blob_size(int *need, int *lbs)
{
int offset;
if (*need <= 0)
return;
offset = ALIGN(*lbs, sizeof(void *));
*lbs = offset + *need;
*need = offset;
}
static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
{
if (!needed)
return;
lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred);
lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file);
lsm_set_blob_size(&needed->lbs_ib, &blob_sizes.lbs_ib);
/*
* The inode blob gets an rcu_head in addition to
* what the modules might need.
*/
if (needed->lbs_inode && blob_sizes.lbs_inode == 0)
blob_sizes.lbs_inode = sizeof(struct rcu_head);
lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key);
lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
lsm_set_blob_size(&needed->lbs_perf_event, &blob_sizes.lbs_perf_event);
lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
lsm_set_blob_size(&needed->lbs_tun_dev, &blob_sizes.lbs_tun_dev);
lsm_set_blob_size(&needed->lbs_xattr_count,
&blob_sizes.lbs_xattr_count);
lsm_set_blob_size(&needed->lbs_bdev, &blob_sizes.lbs_bdev);
}
/* Prepare LSM for initialization. */
static void __init prepare_lsm(struct lsm_info *lsm)
{
int enabled = lsm_allowed(lsm);
/* Record enablement (to handle any following exclusive LSMs). */
set_enabled(lsm, enabled);
/* If enabled, do pre-initialization work. */
if (enabled) {
if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) {
exclusive = lsm;
init_debug("exclusive chosen: %s\n", lsm->name);
}
lsm_set_blob_sizes(lsm->blobs);
}
}
/* Initialize a given LSM, if it is enabled. */
static void __init initialize_lsm(struct lsm_info *lsm)
{
if (is_enabled(lsm)) {
int ret;
init_debug("initializing %s\n", lsm->name);
ret = lsm->init();
WARN(ret, "%s failed to initialize: %d\n", lsm->name, ret);
}
}
/*
* Current index to use while initializing the lsm id list.
*/
u32 lsm_active_cnt __ro_after_init;
const struct lsm_id *lsm_idlist[MAX_LSM_COUNT];
/* Populate ordered LSMs list from comma-separated LSM name list. */
static void __init ordered_lsm_parse(const char *order, const char *origin)
{
struct lsm_info *lsm;
char *sep, *name, *next;
/* LSM_ORDER_FIRST is always first. */
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if (lsm->order == LSM_ORDER_FIRST)
append_ordered_lsm(lsm, " first");
}
/* Process "security=", if given. */
if (chosen_major_lsm) {
struct lsm_info *major;
/*
* To match the original "security=" behavior, this
* explicitly does NOT fallback to another Legacy Major
* if the selected one was separately disabled: disable
* all non-matching Legacy Major LSMs.
*/
for (major = __start_lsm_info; major < __end_lsm_info;
major++) {
if ((major->flags & LSM_FLAG_LEGACY_MAJOR) &&
strcmp(major->name, chosen_major_lsm) != 0) {
set_enabled(major, false);
init_debug("security=%s disabled: %s (only one legacy major LSM)\n",
chosen_major_lsm, major->name);
}
}
}
sep = kstrdup(order, GFP_KERNEL);
next = sep;
/* Walk the list, looking for matching LSMs. */
while ((name = strsep(&next, ",")) != NULL) {
bool found = false;
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if (strcmp(lsm->name, name) == 0) {
if (lsm->order == LSM_ORDER_MUTABLE)
append_ordered_lsm(lsm, origin);
found = true;
}
}
if (!found)
init_debug("%s ignored: %s (not built into kernel)\n",
origin, name);
}
/* Process "security=", if given. */
if (chosen_major_lsm) {
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if (exists_ordered_lsm(lsm))
continue;
if (strcmp(lsm->name, chosen_major_lsm) == 0)
append_ordered_lsm(lsm, "security=");
}
}
/* LSM_ORDER_LAST is always last. */
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if (lsm->order == LSM_ORDER_LAST)
append_ordered_lsm(lsm, " last");
}
/* Disable all LSMs not in the ordered list. */
for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) {
if (exists_ordered_lsm(lsm))
continue;
set_enabled(lsm, false);
init_debug("%s skipped: %s (not in requested order)\n",
origin, lsm->name);
}
kfree(sep);
}
static void __init lsm_static_call_init(struct security_hook_list *hl)
{
struct lsm_static_call *scall = hl->scalls;
int i;
for (i = 0; i < MAX_LSM_COUNT; i++) {
/* Update the first static call that is not used yet */
if (!scall->hl) {
__static_call_update(scall->key, scall->trampoline,
hl->hook.lsm_func_addr);
scall->hl = hl;
static_branch_enable(scall->active);
return;
}
scall++;
}
panic("%s - Ran out of static slots.\n", __func__);
}
static void __init lsm_early_cred(struct cred *cred);
static void __init lsm_early_task(struct task_struct *task);
static int lsm_append(const char *new, char **result);
static void __init report_lsm_order(void)
{
struct lsm_info **lsm, *early;
int first = 0;
pr_info("initializing lsm=");
/* Report each enabled LSM name, comma separated. */
for (early = __start_early_lsm_info;
early < __end_early_lsm_info; early++)
if (is_enabled(early))
pr_cont("%s%s", first++ == 0 ? "" : ",", early->name);
for (lsm = ordered_lsms; *lsm; lsm++)
if (is_enabled(*lsm))
pr_cont("%s%s", first++ == 0 ? "" : ",", (*lsm)->name);
pr_cont("\n");
}
static void __init ordered_lsm_init(void)
{
struct lsm_info **lsm;
if (chosen_lsm_order) {
if (chosen_major_lsm) {
pr_warn("security=%s is ignored because it is superseded by lsm=%s\n",
chosen_major_lsm, chosen_lsm_order);
chosen_major_lsm = NULL;
}
ordered_lsm_parse(chosen_lsm_order, "cmdline");
} else
ordered_lsm_parse(builtin_lsm_order, "builtin");
for (lsm = ordered_lsms; *lsm; lsm++)
prepare_lsm(*lsm);
report_lsm_order();
init_debug("cred blob size = %d\n", blob_sizes.lbs_cred);
init_debug("file blob size = %d\n", blob_sizes.lbs_file);
init_debug("ib blob size = %d\n", blob_sizes.lbs_ib);
init_debug("inode blob size = %d\n", blob_sizes.lbs_inode);
init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc);
#ifdef CONFIG_KEYS
init_debug("key blob size = %d\n", blob_sizes.lbs_key);
#endif /* CONFIG_KEYS */
init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg);
init_debug("sock blob size = %d\n", blob_sizes.lbs_sock);
init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
init_debug("perf event blob size = %d\n", blob_sizes.lbs_perf_event);
init_debug("task blob size = %d\n", blob_sizes.lbs_task);
init_debug("tun device blob size = %d\n", blob_sizes.lbs_tun_dev);
init_debug("xattr slots = %d\n", blob_sizes.lbs_xattr_count);
init_debug("bdev blob size = %d\n", blob_sizes.lbs_bdev);
/*
* Create any kmem_caches needed for blobs
*/
if (blob_sizes.lbs_file)
lsm_file_cache = kmem_cache_create("lsm_file_cache",
blob_sizes.lbs_file, 0,
SLAB_PANIC, NULL);
if (blob_sizes.lbs_inode)
lsm_inode_cache = kmem_cache_create("lsm_inode_cache",
blob_sizes.lbs_inode, 0,
SLAB_PANIC, NULL);
lsm_early_cred((struct cred *) current->cred);
lsm_early_task(current);
for (lsm = ordered_lsms; *lsm; lsm++)
initialize_lsm(*lsm);
}
int __init early_security_init(void)
{
struct lsm_info *lsm;
for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) {
if (!lsm->enabled)
lsm->enabled = &lsm_enabled_true;
prepare_lsm(lsm);
initialize_lsm(lsm);
}
return 0;
}
/**
* security_init - initializes the security framework
*
* This should be called early in the kernel initialization sequence.
*/
int __init security_init(void)
{
struct lsm_info *lsm;
init_debug("legacy security=%s\n", chosen_major_lsm ? : " *unspecified*");
init_debug(" CONFIG_LSM=%s\n", builtin_lsm_order);
init_debug("boot arg lsm=%s\n", chosen_lsm_order ? : " *unspecified*");
/*
* Append the names of the early LSM modules now that kmalloc() is
* available
*/
for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) {
init_debug(" early started: %s (%s)\n", lsm->name,
is_enabled(lsm) ? "enabled" : "disabled");
if (lsm->enabled)
lsm_append(lsm->name, &lsm_names);
}
/* Load LSMs in specified order. */
ordered_lsm_init();
return 0;
}
/* Save user chosen LSM */
static int __init choose_major_lsm(char *str)
{
chosen_major_lsm = str;
return 1;
}
__setup("security=", choose_major_lsm);
/* Explicitly choose LSM initialization order. */
static int __init choose_lsm_order(char *str)
{
chosen_lsm_order = str;
return 1;
}
__setup("lsm=", choose_lsm_order);
/* Enable LSM order debugging. */
static int __init enable_debug(char *str)
{
debug = true;
return 1;
}
__setup("lsm.debug", enable_debug);
static bool match_last_lsm(const char *list, const char *lsm)
{
const char *last;
if (WARN_ON(!list || !lsm))
return false;
last = strrchr(list, ',');
if (last)
/* Pass the comma, strcmp() will check for '\0' */
last++;
else
last = list;
return !strcmp(last, lsm);
}
static int lsm_append(const char *new, char **result)
{
char *cp;
if (*result == NULL) {
*result = kstrdup(new, GFP_KERNEL);
if (*result == NULL)
return -ENOMEM;
} else {
/* Check if it is the last registered name */
if (match_last_lsm(*result, new))
return 0;
cp = kasprintf(GFP_KERNEL, "%s,%s", *result, new);
if (cp == NULL)
return -ENOMEM;
kfree(*result);
*result = cp;
}
return 0;
}
/**
* security_add_hooks - Add a modules hooks to the hook lists.
* @hooks: the hooks to add
* @count: the number of hooks to add
* @lsmid: the identification information for the security module
*
* Each LSM has to register its hooks with the infrastructure.
*/
void __init security_add_hooks(struct security_hook_list *hooks, int count,
const struct lsm_id *lsmid)
{
int i;
/*
* A security module may call security_add_hooks() more
* than once during initialization, and LSM initialization
* is serialized. Landlock is one such case.
* Look at the previous entry, if there is one, for duplication.
*/
if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) {
if (lsm_active_cnt >= MAX_LSM_COUNT)
panic("%s Too many LSMs registered.\n", __func__);
lsm_idlist[lsm_active_cnt++] = lsmid;
}
for (i = 0; i < count; i++) {
hooks[i].lsmid = lsmid;
lsm_static_call_init(&hooks[i]);
}
/*
* Don't try to append during early_security_init(), we'll come back
* and fix this up afterwards.
*/
if (slab_is_available()) {
if (lsm_append(lsmid->name, &lsm_names) < 0)
panic("%s - Cannot get early memory.\n", __func__);
}
}
int call_blocking_lsm_notifier(enum lsm_event event, void *data)
{
return blocking_notifier_call_chain(&blocking_lsm_notifier_chain,
event, data);
}
EXPORT_SYMBOL(call_blocking_lsm_notifier);
int register_blocking_lsm_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&blocking_lsm_notifier_chain,
nb);
}
EXPORT_SYMBOL(register_blocking_lsm_notifier);
int unregister_blocking_lsm_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&blocking_lsm_notifier_chain,
nb);
}
EXPORT_SYMBOL(unregister_blocking_lsm_notifier);
/**
* lsm_blob_alloc - allocate a composite blob
* @dest: the destination for the blob
* @size: the size of the blob
* @gfp: allocation type
*
* Allocate a blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_blob_alloc(void **dest, size_t size, gfp_t gfp)
{
if (size == 0) {
*dest = NULL;
return 0;
}
*dest = kzalloc(size, gfp);
if (*dest == NULL)
return -ENOMEM;
return 0;
}
/**
* lsm_cred_alloc - allocate a composite cred blob
* @cred: the cred that needs a blob
* @gfp: allocation type
*
* Allocate the cred blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_cred_alloc(struct cred *cred, gfp_t gfp)
{
return lsm_blob_alloc(&cred->security, blob_sizes.lbs_cred, gfp);
}
/**
* lsm_early_cred - during initialization allocate a composite cred blob
* @cred: the cred that needs a blob
*
* Allocate the cred blob for all the modules
*/
static void __init lsm_early_cred(struct cred *cred)
{
int rc = lsm_cred_alloc(cred, GFP_KERNEL);
if (rc)
panic("%s: Early cred alloc failed.\n", __func__);
}
/**
* lsm_file_alloc - allocate a composite file blob
* @file: the file that needs a blob
*
* Allocate the file blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_file_alloc(struct file *file)
{
if (!lsm_file_cache) {
file->f_security = NULL;
return 0;
}
file->f_security = kmem_cache_zalloc(lsm_file_cache, GFP_KERNEL);
if (file->f_security == NULL)
return -ENOMEM;
return 0;
}
/**
* lsm_inode_alloc - allocate a composite inode blob
* @inode: the inode that needs a blob
*
* Allocate the inode blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_inode_alloc(struct inode *inode)
{
if (!lsm_inode_cache) {
inode->i_security = NULL;
return 0;
}
inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_NOFS);
if (inode->i_security == NULL)
return -ENOMEM;
return 0;
}
/**
* lsm_task_alloc - allocate a composite task blob
* @task: the task that needs a blob
*
* Allocate the task blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_task_alloc(struct task_struct *task)
{
return lsm_blob_alloc(&task->security, blob_sizes.lbs_task, GFP_KERNEL);
}
/**
* lsm_ipc_alloc - allocate a composite ipc blob
* @kip: the ipc that needs a blob
*
* Allocate the ipc blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_ipc_alloc(struct kern_ipc_perm *kip)
{
return lsm_blob_alloc(&kip->security, blob_sizes.lbs_ipc, GFP_KERNEL);
}
#ifdef CONFIG_KEYS
/**
* lsm_key_alloc - allocate a composite key blob
* @key: the key that needs a blob
*
* Allocate the key blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_key_alloc(struct key *key)
{
return lsm_blob_alloc(&key->security, blob_sizes.lbs_key, GFP_KERNEL);
}
#endif /* CONFIG_KEYS */
/**
* lsm_msg_msg_alloc - allocate a composite msg_msg blob
* @mp: the msg_msg that needs a blob
*
* Allocate the ipc blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_msg_msg_alloc(struct msg_msg *mp)
{
return lsm_blob_alloc(&mp->security, blob_sizes.lbs_msg_msg,
GFP_KERNEL);
}
/**
* lsm_bdev_alloc - allocate a composite block_device blob
* @bdev: the block_device that needs a blob
*
* Allocate the block_device blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_bdev_alloc(struct block_device *bdev)
{
if (blob_sizes.lbs_bdev == 0) {
bdev->bd_security = NULL;
return 0;
}
bdev->bd_security = kzalloc(blob_sizes.lbs_bdev, GFP_KERNEL);
if (!bdev->bd_security)
return -ENOMEM;
return 0;
}
/**
* lsm_early_task - during initialization allocate a composite task blob
* @task: the task that needs a blob
*
* Allocate the task blob for all the modules
*/
static void __init lsm_early_task(struct task_struct *task)
{
int rc = lsm_task_alloc(task);
if (rc)
panic("%s: Early task alloc failed.\n", __func__);
}
/**
* lsm_superblock_alloc - allocate a composite superblock blob
* @sb: the superblock that needs a blob
*
* Allocate the superblock blob for all the modules
*
* Returns 0, or -ENOMEM if memory can't be allocated.
*/
static int lsm_superblock_alloc(struct super_block *sb)
{
return lsm_blob_alloc(&sb->s_security, blob_sizes.lbs_superblock,
GFP_KERNEL);
}
/**
* lsm_fill_user_ctx - Fill a user space lsm_ctx structure
* @uctx: a userspace LSM context to be filled
* @uctx_len: available uctx size (input), used uctx size (output)
* @val: the new LSM context value
* @val_len: the size of the new LSM context value
* @id: LSM id
* @flags: LSM defined flags
*
* Fill all of the fields in a userspace lsm_ctx structure. If @uctx is NULL
* simply calculate the required size to output via @utc_len and return
* success.
*
* Returns 0 on success, -E2BIG if userspace buffer is not large enough,
* -EFAULT on a copyout error, -ENOMEM if memory can't be allocated.
*/
int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, u32 *uctx_len,
void *val, size_t val_len,
u64 id, u64 flags)
{
struct lsm_ctx *nctx = NULL;
size_t nctx_len;
int rc = 0;
nctx_len = ALIGN(struct_size(nctx, ctx, val_len), sizeof(void *));
if (nctx_len > *uctx_len) {
rc = -E2BIG;
goto out;
}
/* no buffer - return success/0 and set @uctx_len to the req size */
if (!uctx)
goto out;
nctx = kzalloc(nctx_len, GFP_KERNEL);
if (nctx == NULL) {
rc = -ENOMEM;
goto out;
}
nctx->id = id;
nctx->flags = flags;
nctx->len = nctx_len;
nctx->ctx_len = val_len;
memcpy(nctx->ctx, val, val_len);
if (copy_to_user(uctx, nctx, nctx_len))
rc = -EFAULT;
out:
kfree(nctx);
*uctx_len = nctx_len;
return rc;
}
/*
* The default value of the LSM hook is defined in linux/lsm_hook_defs.h and
* can be accessed with:
*
* LSM_RET_DEFAULT(<hook_name>)
*
* The macros below define static constants for the default value of each
* LSM hook.
*/
#define LSM_RET_DEFAULT(NAME) (NAME##_default)
#define DECLARE_LSM_RET_DEFAULT_void(DEFAULT, NAME)
#define DECLARE_LSM_RET_DEFAULT_int(DEFAULT, NAME) \
static const int __maybe_unused LSM_RET_DEFAULT(NAME) = (DEFAULT);
#define LSM_HOOK(RET, DEFAULT, NAME, ...) \
DECLARE_LSM_RET_DEFAULT_##RET(DEFAULT, NAME)
#include <linux/lsm_hook_defs.h>
#undef LSM_HOOK
/*
* Hook list operation macros.
*
* call_void_hook:
* This is a hook that does not return a value.
*
* call_int_hook:
* This is a hook that returns a value.
*/
#define __CALL_STATIC_VOID(NUM, HOOK, ...) \
do { \
if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \
static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \
} \
} while (0);
#define call_void_hook(HOOK, ...) \
do { \
LSM_LOOP_UNROLL(__CALL_STATIC_VOID, HOOK, __VA_ARGS__); \
} while (0)
#define __CALL_STATIC_INT(NUM, R, HOOK, LABEL, ...) \
do { \
if (static_branch_unlikely(&SECURITY_HOOK_ACTIVE_KEY(HOOK, NUM))) { \
R = static_call(LSM_STATIC_CALL(HOOK, NUM))(__VA_ARGS__); \
if (R != LSM_RET_DEFAULT(HOOK)) \
goto LABEL; \
} \
} while (0);
#define call_int_hook(HOOK, ...) \
({ \
__label__ OUT; \
int RC = LSM_RET_DEFAULT(HOOK); \
\
LSM_LOOP_UNROLL(__CALL_STATIC_INT, RC, HOOK, OUT, __VA_ARGS__); \
OUT: \
RC; \
})
#define lsm_for_each_hook(scall, NAME) \
for (scall = static_calls_table.NAME; \
scall - static_calls_table.NAME < MAX_LSM_COUNT; scall++) \
if (static_key_enabled(&scall->active->key))
/* Security operations */
/**
* security_binder_set_context_mgr() - Check if becoming binder ctx mgr is ok
* @mgr: task credentials of current binder process
*
* Check whether @mgr is allowed to be the binder context manager.
*
* Return: Return 0 if permission is granted.
*/
int security_binder_set_context_mgr(const struct cred *mgr)
{
return call_int_hook(binder_set_context_mgr, mgr);
}
/**
* security_binder_transaction() - Check if a binder transaction is allowed
* @from: sending process
* @to: receiving process
*
* Check whether @from is allowed to invoke a binder transaction call to @to.
*
* Return: Returns 0 if permission is granted.
*/
int security_binder_transaction(const struct cred *from,
const struct cred *to)
{
return call_int_hook(binder_transaction, from, to);
}
/**
* security_binder_transfer_binder() - Check if a binder transfer is allowed
* @from: sending process
* @to: receiving process
*
* Check whether @from is allowed to transfer a binder reference to @to.
*
* Return: Returns 0 if permission is granted.
*/
int security_binder_transfer_binder(const struct cred *from,
const struct cred *to)
{
return call_int_hook(binder_transfer_binder, from, to);
}
/**
* security_binder_transfer_file() - Check if a binder file xfer is allowed
* @from: sending process
* @to: receiving process
* @file: file being transferred
*
* Check whether @from is allowed to transfer @file to @to.
*
* Return: Returns 0 if permission is granted.
*/
int security_binder_transfer_file(const struct cred *from,
const struct cred *to, const struct file *file)
{
return call_int_hook(binder_transfer_file, from, to, file);
}
/**
* security_ptrace_access_check() - Check if tracing is allowed
* @child: target process
* @mode: PTRACE_MODE flags
*
* Check permission before allowing the current process to trace the @child
* process. Security modules may also want to perform a process tracing check
* during an execve in the set_security or apply_creds hooks of tracing check
* during an execve in the bprm_set_creds hook of binprm_security_ops if the
* process is being traced and its security attributes would be changed by the
* execve.
*
* Return: Returns 0 if permission is granted.
*/
int security_ptrace_access_check(struct task_struct *child, unsigned int mode)
{
return call_int_hook(ptrace_access_check, child, mode);
}
/**
* security_ptrace_traceme() - Check if tracing is allowed
* @parent: tracing process
*
* Check that the @parent process has sufficient permission to trace the
* current process before allowing the current process to present itself to the
* @parent process for tracing.
*
* Return: Returns 0 if permission is granted.
*/
int security_ptrace_traceme(struct task_struct *parent)
{
return call_int_hook(ptrace_traceme, parent);
}
/**
* security_capget() - Get the capability sets for a process
* @target: target process
* @effective: effective capability set
* @inheritable: inheritable capability set
* @permitted: permitted capability set
*
* Get the @effective, @inheritable, and @permitted capability sets for the
* @target process. The hook may also perform permission checking to determine
* if the current process is allowed to see the capability sets of the @target
* process.
*
* Return: Returns 0 if the capability sets were successfully obtained.
*/
int security_capget(const struct task_struct *target,
kernel_cap_t *effective,
kernel_cap_t *inheritable,
kernel_cap_t *permitted)
{
return call_int_hook(capget, target, effective, inheritable, permitted);
}
/**
* security_capset() - Set the capability sets for a process
* @new: new credentials for the target process
* @old: current credentials of the target process
* @effective: effective capability set
* @inheritable: inheritable capability set
* @permitted: permitted capability set
*
* Set the @effective, @inheritable, and @permitted capability sets for the
* current process.
*
* Return: Returns 0 and update @new if permission is granted.
*/
int security_capset(struct cred *new, const struct cred *old,
const kernel_cap_t *effective,
const kernel_cap_t *inheritable,
const kernel_cap_t *permitted)
{
return call_int_hook(capset, new, old, effective, inheritable,
permitted);
}
/**
* security_capable() - Check if a process has the necessary capability
* @cred: credentials to examine
* @ns: user namespace
* @cap: capability requested
* @opts: capability check options
*
* Check whether the @tsk process has the @cap capability in the indicated
* credentials. @cap contains the capability <include/linux/capability.h>.
* @opts contains options for the capable check <include/linux/security.h>.
*
* Return: Returns 0 if the capability is granted.
*/
int security_capable(const struct cred *cred,
struct user_namespace *ns,
int cap,
unsigned int opts)
{
return call_int_hook(capable, cred, ns, cap, opts);
}
/**
* security_quotactl() - Check if a quotactl() syscall is allowed for this fs
* @cmds: commands
* @type: type
* @id: id
* @sb: filesystem
*
* Check whether the quotactl syscall is allowed for this @sb.
*
* Return: Returns 0 if permission is granted.
*/
int security_quotactl(int cmds, int type, int id, const struct super_block *sb)
{
return call_int_hook(quotactl, cmds, type, id, sb);
}
/**
* security_quota_on() - Check if QUOTAON is allowed for a dentry
* @dentry: dentry
*
* Check whether QUOTAON is allowed for @dentry.
*
* Return: Returns 0 if permission is granted.
*/
int security_quota_on(struct dentry *dentry)
{
return call_int_hook(quota_on, dentry);
}
/**
* security_syslog() - Check if accessing the kernel message ring is allowed
* @type: SYSLOG_ACTION_* type
*
* Check permission before accessing the kernel message ring or changing
* logging to the console. See the syslog(2) manual page for an explanation of
* the @type values.
*
* Return: Return 0 if permission is granted.
*/
int security_syslog(int type)
{
return call_int_hook(syslog, type);
}
/**
* security_settime64() - Check if changing the system time is allowed
* @ts: new time
* @tz: timezone
*
* Check permission to change the system time, struct timespec64 is defined in
* <include/linux/time64.h> and timezone is defined in <include/linux/time.h>.
*
* Return: Returns 0 if permission is granted.
*/
int security_settime64(const struct timespec64 *ts, const struct timezone *tz)
{
return call_int_hook(settime, ts, tz);
}
/**
* security_vm_enough_memory_mm() - Check if allocating a new mem map is allowed
* @mm: mm struct
* @pages: number of pages
*
* Check permissions for allocating a new virtual mapping. If all LSMs return
* a positive value, __vm_enough_memory() will be called with cap_sys_admin
* set. If at least one LSM returns 0 or negative, __vm_enough_memory() will be
* called with cap_sys_admin cleared.
*
* Return: Returns 0 if permission is granted by the LSM infrastructure to the
* caller.
*/
int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
{
struct lsm_static_call *scall;
int cap_sys_admin = 1;
int rc;
/*
* The module will respond with 0 if it thinks the __vm_enough_memory()
* call should be made with the cap_sys_admin set. If all of the modules
* agree that it should be set it will. If any module thinks it should
* not be set it won't.
*/
lsm_for_each_hook(scall, vm_enough_memory) {
rc = scall->hl->hook.vm_enough_memory(mm, pages);
if (rc < 0) {
cap_sys_admin = 0;
break;
}
}
return __vm_enough_memory(mm, pages, cap_sys_admin);
}
/**
* security_bprm_creds_for_exec() - Prepare the credentials for exec()
* @bprm: binary program information
*
* If the setup in prepare_exec_creds did not setup @bprm->cred->security
* properly for executing @bprm->file, update the LSM's portion of
* @bprm->cred->security to be what commit_creds needs to install for the new
* program. This hook may also optionally check permissions (e.g. for
* transitions between security domains). The hook must set @bprm->secureexec
* to 1 if AT_SECURE should be set to request libc enable secure mode. @bprm
* contains the linux_binprm structure.
*
* Return: Returns 0 if the hook is successful and permission is granted.
*/
int security_bprm_creds_for_exec(struct linux_binprm *bprm)
{
return call_int_hook(bprm_creds_for_exec, bprm);
}
/**
* security_bprm_creds_from_file() - Update linux_binprm creds based on file
* @bprm: binary program information
* @file: associated file
*
* If @file is setpcap, suid, sgid or otherwise marked to change privilege upon
* exec, update @bprm->cred to reflect that change. This is called after
* finding the binary that will be executed without an interpreter. This
* ensures that the credentials will not be derived from a script that the
* binary will need to reopen, which when reopend may end up being a completely
* different file. This hook may also optionally check permissions (e.g. for
* transitions between security domains). The hook must set @bprm->secureexec
* to 1 if AT_SECURE should be set to request libc enable secure mode. The
* hook must add to @bprm->per_clear any personality flags that should be
* cleared from current->personality. @bprm contains the linux_binprm
* structure.
*
* Return: Returns 0 if the hook is successful and permission is granted.
*/
int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file)
{
return call_int_hook(bprm_creds_from_file, bprm, file);
}
/**
* security_bprm_check() - Mediate binary handler search
* @bprm: binary program information
*
* This hook mediates the point when a search for a binary handler will begin.
* It allows a check against the @bprm->cred->security value which was set in
* the preceding creds_for_exec call. The argv list and envp list are reliably
* available in @bprm. This hook may be called multiple times during a single
* execve. @bprm contains the linux_binprm structure.
*
* Return: Returns 0 if the hook is successful and permission is granted.
*/
int security_bprm_check(struct linux_binprm *bprm)
{
return call_int_hook(bprm_check_security, bprm);
}
/**
* security_bprm_committing_creds() - Install creds for a process during exec()
* @bprm: binary program information
*
* Prepare to install the new security attributes of a process being
* transformed by an execve operation, based on the old credentials pointed to
* by @current->cred and the information set in @bprm->cred by the
* bprm_creds_for_exec hook. @bprm points to the linux_binprm structure. This
* hook is a good place to perform state changes on the process such as closing
* open file descriptors to which access will no longer be granted when the
* attributes are changed. This is called immediately before commit_creds().
*/
void security_bprm_committing_creds(const struct linux_binprm *bprm)
{
call_void_hook(bprm_committing_creds, bprm);
}
/**
* security_bprm_committed_creds() - Tidy up after cred install during exec()
* @bprm: binary program information
*
* Tidy up after the installation of the new security attributes of a process
* being transformed by an execve operation. The new credentials have, by this
* point, been set to @current->cred. @bprm points to the linux_binprm
* structure. This hook is a good place to perform state changes on the
* process such as clearing out non-inheritable signal state. This is called
* immediately after commit_creds().
*/
void security_bprm_committed_creds(const struct linux_binprm *bprm)
{
call_void_hook(bprm_committed_creds, bprm);
}
/**
* security_fs_context_submount() - Initialise fc->security
* @fc: new filesystem context
* @reference: dentry reference for submount/remount
*
* Fill out the ->security field for a new fs_context.
*
* Return: Returns 0 on success or negative error code on failure.
*/
int security_fs_context_submount(struct fs_context *fc, struct super_block *reference)
{
return call_int_hook(fs_context_submount, fc, reference);
}
/**
* security_fs_context_dup() - Duplicate a fs_context LSM blob
* @fc: destination filesystem context
* @src_fc: source filesystem context
*
* Allocate and attach a security structure to sc->security. This pointer is
* initialised to NULL by the caller. @fc indicates the new filesystem context.
* @src_fc indicates the original filesystem context.
*
* Return: Returns 0 on success or a negative error code on failure.
*/
int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
{
return call_int_hook(fs_context_dup, fc, src_fc);
}
/**
* security_fs_context_parse_param() - Configure a filesystem context
* @fc: filesystem context
* @param: filesystem parameter
*
* Userspace provided a parameter to configure a superblock. The LSM can
* consume the parameter or return it to the caller for use elsewhere.
*
* Return: If the parameter is used by the LSM it should return 0, if it is
* returned to the caller -ENOPARAM is returned, otherwise a negative
* error code is returned.
*/
int security_fs_context_parse_param(struct fs_context *fc,
struct fs_parameter *param)
{
struct lsm_static_call *scall;
int trc;
int rc = -ENOPARAM;
lsm_for_each_hook(scall, fs_context_parse_param) {
trc = scall->hl->hook.fs_context_parse_param(fc, param);
if (trc == 0)
rc = 0;
else if (trc != -ENOPARAM)
return trc;
}
return rc;
}
/**
* security_sb_alloc() - Allocate a super_block LSM blob
* @sb: filesystem superblock
*
* Allocate and attach a security structure to the sb->s_security field. The
* s_security field is initialized to NULL when the structure is allocated.
* @sb contains the super_block structure to be modified.
*
* Return: Returns 0 if operation was successful.
*/
int security_sb_alloc(struct super_block *sb)
{
int rc = lsm_superblock_alloc(sb);
if (unlikely(rc))
return rc;
rc = call_int_hook(sb_alloc_security, sb);
if (unlikely(rc))
security_sb_free(sb);
return rc;
}
/**
* security_sb_delete() - Release super_block LSM associated objects
* @sb: filesystem superblock
*
* Release objects tied to a superblock (e.g. inodes). @sb contains the
* super_block structure being released.
*/
void security_sb_delete(struct super_block *sb)
{
call_void_hook(sb_delete, sb);
}
/**
* security_sb_free() - Free a super_block LSM blob
* @sb: filesystem superblock
*
* Deallocate and clear the sb->s_security field. @sb contains the super_block
* structure to be modified.
*/
void security_sb_free(struct super_block *sb)
{
call_void_hook(sb_free_security, sb);
kfree(sb->s_security);
sb->s_security = NULL;
}
/**
* security_free_mnt_opts() - Free memory associated with mount options
* @mnt_opts: LSM processed mount options
*
* Free memory associated with @mnt_ops.
*/
void security_free_mnt_opts(void **mnt_opts)
{
if (!*mnt_opts)
return;
call_void_hook(sb_free_mnt_opts, *mnt_opts);
*mnt_opts = NULL;
}
EXPORT_SYMBOL(security_free_mnt_opts);
/**
* security_sb_eat_lsm_opts() - Consume LSM mount options
* @options: mount options
* @mnt_opts: LSM processed mount options
*
* Eat (scan @options) and save them in @mnt_opts.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
return call_int_hook(sb_eat_lsm_opts, options, mnt_opts);
}
EXPORT_SYMBOL(security_sb_eat_lsm_opts);
/**
* security_sb_mnt_opts_compat() - Check if new mount options are allowed
* @sb: filesystem superblock
* @mnt_opts: new mount options
*
* Determine if the new mount options in @mnt_opts are allowed given the
* existing mounted filesystem at @sb. @sb superblock being compared.
*
* Return: Returns 0 if options are compatible.
*/
int security_sb_mnt_opts_compat(struct super_block *sb,
void *mnt_opts)
{
return call_int_hook(sb_mnt_opts_compat, sb, mnt_opts);
}
EXPORT_SYMBOL(security_sb_mnt_opts_compat);
/**
* security_sb_remount() - Verify no incompatible mount changes during remount
* @sb: filesystem superblock
* @mnt_opts: (re)mount options
*
* Extracts security system specific mount options and verifies no changes are
* being made to those options.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_remount(struct super_block *sb,
void *mnt_opts)
{
return call_int_hook(sb_remount, sb, mnt_opts);
}
EXPORT_SYMBOL(security_sb_remount);
/**
* security_sb_kern_mount() - Check if a kernel mount is allowed
* @sb: filesystem superblock
*
* Mount this @sb if allowed by permissions.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_kern_mount(const struct super_block *sb)
{
return call_int_hook(sb_kern_mount, sb);
}
/**
* security_sb_show_options() - Output the mount options for a superblock
* @m: output file
* @sb: filesystem superblock
*
* Show (print on @m) mount options for this @sb.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_sb_show_options(struct seq_file *m, struct super_block *sb)
{
return call_int_hook(sb_show_options, m, sb);
}
/**
* security_sb_statfs() - Check if accessing fs stats is allowed
* @dentry: superblock handle
*
* Check permission before obtaining filesystem statistics for the @mnt
* mountpoint. @dentry is a handle on the superblock for the filesystem.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_statfs(struct dentry *dentry)
{
return call_int_hook(sb_statfs, dentry);
}
/**
* security_sb_mount() - Check permission for mounting a filesystem
* @dev_name: filesystem backing device
* @path: mount point
* @type: filesystem type
* @flags: mount flags
* @data: filesystem specific data
*
* Check permission before an object specified by @dev_name is mounted on the
* mount point named by @nd. For an ordinary mount, @dev_name identifies a
* device if the file system type requires a device. For a remount
* (@flags & MS_REMOUNT), @dev_name is irrelevant. For a loopback/bind mount
* (@flags & MS_BIND), @dev_name identifies the pathname of the object being
* mounted.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_mount(const char *dev_name, const struct path *path,
const char *type, unsigned long flags, void *data)
{
return call_int_hook(sb_mount, dev_name, path, type, flags, data);
}
/**
* security_sb_umount() - Check permission for unmounting a filesystem
* @mnt: mounted filesystem
* @flags: unmount flags
*
* Check permission before the @mnt file system is unmounted.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_umount(struct vfsmount *mnt, int flags)
{
return call_int_hook(sb_umount, mnt, flags);
}
/**
* security_sb_pivotroot() - Check permissions for pivoting the rootfs
* @old_path: new location for current rootfs
* @new_path: location of the new rootfs
*
* Check permission before pivoting the root filesystem.
*
* Return: Returns 0 if permission is granted.
*/
int security_sb_pivotroot(const struct path *old_path,
const struct path *new_path)
{
return call_int_hook(sb_pivotroot, old_path, new_path);
}
/**
* security_sb_set_mnt_opts() - Set the mount options for a filesystem
* @sb: filesystem superblock
* @mnt_opts: binary mount options
* @kern_flags: kernel flags (in)
* @set_kern_flags: kernel flags (out)
*
* Set the security relevant mount options used for a superblock.
*
* Return: Returns 0 on success, error on failure.
*/
int security_sb_set_mnt_opts(struct super_block *sb,
void *mnt_opts,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
struct lsm_static_call *scall;
int rc = mnt_opts ? -EOPNOTSUPP : LSM_RET_DEFAULT(sb_set_mnt_opts);
lsm_for_each_hook(scall, sb_set_mnt_opts) {
rc = scall->hl->hook.sb_set_mnt_opts(sb, mnt_opts, kern_flags,
set_kern_flags);
if (rc != LSM_RET_DEFAULT(sb_set_mnt_opts))
break;
}
return rc;
}
EXPORT_SYMBOL(security_sb_set_mnt_opts);
/**
* security_sb_clone_mnt_opts() - Duplicate superblock mount options
* @oldsb: source superblock
* @newsb: destination superblock
* @kern_flags: kernel flags (in)
* @set_kern_flags: kernel flags (out)
*
* Copy all security options from a given superblock to another.
*
* Return: Returns 0 on success, error on failure.
*/
int security_sb_clone_mnt_opts(const struct super_block *oldsb,
struct super_block *newsb,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
return call_int_hook(sb_clone_mnt_opts, oldsb, newsb,
kern_flags, set_kern_flags);
}
EXPORT_SYMBOL(security_sb_clone_mnt_opts);
/**
* security_move_mount() - Check permissions for moving a mount
* @from_path: source mount point
* @to_path: destination mount point
*
* Check permission before a mount is moved.
*
* Return: Returns 0 if permission is granted.
*/
int security_move_mount(const struct path *from_path,
const struct path *to_path)
{
return call_int_hook(move_mount, from_path, to_path);
}
/**
* security_path_notify() - Check if setting a watch is allowed
* @path: file path
* @mask: event mask
* @obj_type: file path type
*
* Check permissions before setting a watch on events as defined by @mask, on
* an object at @path, whose type is defined by @obj_type.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_notify(const struct path *path, u64 mask,
unsigned int obj_type)
{
return call_int_hook(path_notify, path, mask, obj_type);
}
/**
* security_inode_alloc() - Allocate an inode LSM blob
* @inode: the inode
*
* Allocate and attach a security structure to @inode->i_security. The
* i_security field is initialized to NULL when the inode structure is
* allocated.
*
* Return: Return 0 if operation was successful.
*/
int security_inode_alloc(struct inode *inode)
{
int rc = lsm_inode_alloc(inode);
if (unlikely(rc))
return rc;
rc = call_int_hook(inode_alloc_security, inode);
if (unlikely(rc))
security_inode_free(inode);
return rc;
}
static void inode_free_by_rcu(struct rcu_head *head)
{
/* The rcu head is at the start of the inode blob */
call_void_hook(inode_free_security_rcu, head);
kmem_cache_free(lsm_inode_cache, head);
}
/**
* security_inode_free() - Free an inode's LSM blob
* @inode: the inode
*
* Release any LSM resources associated with @inode, although due to the
* inode's RCU protections it is possible that the resources will not be
* fully released until after the current RCU grace period has elapsed.
*
* It is important for LSMs to note that despite being present in a call to
* security_inode_free(), @inode may still be referenced in a VFS path walk
* and calls to security_inode_permission() may be made during, or after,
* a call to security_inode_free(). For this reason the inode->i_security
* field is released via a call_rcu() callback and any LSMs which need to
* retain inode state for use in security_inode_permission() should only
* release that state in the inode_free_security_rcu() LSM hook callback.
*/
void security_inode_free(struct inode *inode)
{
call_void_hook(inode_free_security, inode);
if (!inode->i_security)
return;
call_rcu((struct rcu_head *)inode->i_security, inode_free_by_rcu);
}
/**
* security_dentry_init_security() - Perform dentry initialization
* @dentry: the dentry to initialize
* @mode: mode used to determine resource type
* @name: name of the last path component
* @xattr_name: name of the security/LSM xattr
* @ctx: pointer to the resulting LSM context
* @ctxlen: length of @ctx
*
* Compute a context for a dentry as the inode is not yet available since NFSv4
* has no label backed by an EA anyway. It is important to note that
* @xattr_name does not need to be free'd by the caller, it is a static string.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_dentry_init_security(struct dentry *dentry, int mode,
const struct qstr *name,
const char **xattr_name, void **ctx,
u32 *ctxlen)
{
return call_int_hook(dentry_init_security, dentry, mode, name,
xattr_name, ctx, ctxlen);
}
EXPORT_SYMBOL(security_dentry_init_security);
/**
* security_dentry_create_files_as() - Perform dentry initialization
* @dentry: the dentry to initialize
* @mode: mode used to determine resource type
* @name: name of the last path component
* @old: creds to use for LSM context calculations
* @new: creds to modify
*
* Compute a context for a dentry as the inode is not yet available and set
* that context in passed in creds so that new files are created using that
* context. Context is calculated using the passed in creds and not the creds
* of the caller.
*
* Return: Returns 0 on success, error on failure.
*/
int security_dentry_create_files_as(struct dentry *dentry, int mode,
struct qstr *name,
const struct cred *old, struct cred *new)
{
return call_int_hook(dentry_create_files_as, dentry, mode,
name, old, new);
}
EXPORT_SYMBOL(security_dentry_create_files_as);
/**
* security_inode_init_security() - Initialize an inode's LSM context
* @inode: the inode
* @dir: parent directory
* @qstr: last component of the pathname
* @initxattrs: callback function to write xattrs
* @fs_data: filesystem specific data
*
* Obtain the security attribute name suffix and value to set on a newly
* created inode and set up the incore security field for the new inode. This
* hook is called by the fs code as part of the inode creation transaction and
* provides for atomic labeling of the inode, unlike the post_create/mkdir/...
* hooks called by the VFS.
*
* The hook function is expected to populate the xattrs array, by calling
* lsm_get_xattr_slot() to retrieve the slots reserved by the security module
* with the lbs_xattr_count field of the lsm_blob_sizes structure. For each
* slot, the hook function should set ->name to the attribute name suffix
* (e.g. selinux), to allocate ->value (will be freed by the caller) and set it
* to the attribute value, to set ->value_len to the length of the value. If
* the security module does not use security attributes or does not wish to put
* a security attribute on this particular inode, then it should return
* -EOPNOTSUPP to skip this processing.
*
* Return: Returns 0 if the LSM successfully initialized all of the inode
* security attributes that are required, negative values otherwise.
*/
int security_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr,
const initxattrs initxattrs, void *fs_data)
{
struct lsm_static_call *scall;
struct xattr *new_xattrs = NULL;
int ret = -EOPNOTSUPP, xattr_count = 0;
if (unlikely(IS_PRIVATE(inode)))
return 0;
if (!blob_sizes.lbs_xattr_count)
return 0;
if (initxattrs) {
/* Allocate +1 as terminator. */
new_xattrs = kcalloc(blob_sizes.lbs_xattr_count + 1,
sizeof(*new_xattrs), GFP_NOFS);
if (!new_xattrs)
return -ENOMEM;
}
lsm_for_each_hook(scall, inode_init_security) {
ret = scall->hl->hook.inode_init_security(inode, dir, qstr, new_xattrs,
&xattr_count);
if (ret && ret != -EOPNOTSUPP)
goto out;
/*
* As documented in lsm_hooks.h, -EOPNOTSUPP in this context
* means that the LSM is not willing to provide an xattr, not
* that it wants to signal an error. Thus, continue to invoke
* the remaining LSMs.
*/
}
/* If initxattrs() is NULL, xattr_count is zero, skip the call. */
if (!xattr_count)
goto out;
ret = initxattrs(inode, new_xattrs, fs_data);
out:
for (; xattr_count > 0; xattr_count--)
kfree(new_xattrs[xattr_count - 1].value);
kfree(new_xattrs);
return (ret == -EOPNOTSUPP) ? 0 : ret;
}
EXPORT_SYMBOL(security_inode_init_security);
/**
* security_inode_init_security_anon() - Initialize an anonymous inode
* @inode: the inode
* @name: the anonymous inode class
* @context_inode: an optional related inode
*
* Set up the incore security field for the new anonymous inode and return
* whether the inode creation is permitted by the security module or not.
*
* Return: Returns 0 on success, -EACCES if the security module denies the
* creation of this inode, or another -errno upon other errors.
*/
int security_inode_init_security_anon(struct inode *inode,
const struct qstr *name,
const struct inode *context_inode)
{
return call_int_hook(inode_init_security_anon, inode, name,
context_inode);
}
#ifdef CONFIG_SECURITY_PATH
/**
* security_path_mknod() - Check if creating a special file is allowed
* @dir: parent directory
* @dentry: new file
* @mode: new file mode
* @dev: device number
*
* Check permissions when creating a file. Note that this hook is called even
* if mknod operation is being done for a regular file.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_mknod(const struct path *dir, struct dentry *dentry,
umode_t mode, unsigned int dev)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry))))
return 0;
return call_int_hook(path_mknod, dir, dentry, mode, dev);
}
EXPORT_SYMBOL(security_path_mknod);
/**
* security_path_post_mknod() - Update inode security after reg file creation
* @idmap: idmap of the mount
* @dentry: new file
*
* Update inode security field after a regular file has been created.
*/
void security_path_post_mknod(struct mnt_idmap *idmap, struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(path_post_mknod, idmap, dentry);
}
/**
* security_path_mkdir() - Check if creating a new directory is allowed
* @dir: parent directory
* @dentry: new directory
* @mode: new directory mode
*
* Check permissions to create a new directory in the existing directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_mkdir(const struct path *dir, struct dentry *dentry,
umode_t mode)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry))))
return 0;
return call_int_hook(path_mkdir, dir, dentry, mode);
}
EXPORT_SYMBOL(security_path_mkdir);
/**
* security_path_rmdir() - Check if removing a directory is allowed
* @dir: parent directory
* @dentry: directory to remove
*
* Check the permission to remove a directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_rmdir(const struct path *dir, struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry))))
return 0;
return call_int_hook(path_rmdir, dir, dentry);
}
/**
* security_path_unlink() - Check if removing a hard link is allowed
* @dir: parent directory
* @dentry: file
*
* Check the permission to remove a hard link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_unlink(const struct path *dir, struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry))))
return 0;
return call_int_hook(path_unlink, dir, dentry);
}
EXPORT_SYMBOL(security_path_unlink);
/**
* security_path_symlink() - Check if creating a symbolic link is allowed
* @dir: parent directory
* @dentry: symbolic link
* @old_name: file pathname
*
* Check the permission to create a symbolic link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_symlink(const struct path *dir, struct dentry *dentry,
const char *old_name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dir->dentry))))
return 0;
return call_int_hook(path_symlink, dir, dentry, old_name);
}
/**
* security_path_link - Check if creating a hard link is allowed
* @old_dentry: existing file
* @new_dir: new parent directory
* @new_dentry: new link
*
* Check permission before creating a new hard link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_link(struct dentry *old_dentry, const struct path *new_dir,
struct dentry *new_dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry))))
return 0;
return call_int_hook(path_link, old_dentry, new_dir, new_dentry);
}
/**
* security_path_rename() - Check if renaming a file is allowed
* @old_dir: parent directory of the old file
* @old_dentry: the old file
* @new_dir: parent directory of the new file
* @new_dentry: the new file
* @flags: flags
*
* Check for permission to rename a file or directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_rename(const struct path *old_dir, struct dentry *old_dentry,
const struct path *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) ||
(d_is_positive(new_dentry) &&
IS_PRIVATE(d_backing_inode(new_dentry)))))
return 0;
return call_int_hook(path_rename, old_dir, old_dentry, new_dir,
new_dentry, flags);
}
EXPORT_SYMBOL(security_path_rename);
/**
* security_path_truncate() - Check if truncating a file is allowed
* @path: file
*
* Check permission before truncating the file indicated by path. Note that
* truncation permissions may also be checked based on already opened files,
* using the security_file_truncate() hook.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_truncate(const struct path *path)
{
if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))
return 0;
return call_int_hook(path_truncate, path);
}
/**
* security_path_chmod() - Check if changing the file's mode is allowed
* @path: file
* @mode: new mode
*
* Check for permission to change a mode of the file @path. The new mode is
* specified in @mode which is a bitmask of constants from
* <include/uapi/linux/stat.h>.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_chmod(const struct path *path, umode_t mode)
{
if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))
return 0;
return call_int_hook(path_chmod, path, mode);
}
/**
* security_path_chown() - Check if changing the file's owner/group is allowed
* @path: file
* @uid: file owner
* @gid: file group
*
* Check for permission to change owner/group of a file or directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
{
if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))
return 0;
return call_int_hook(path_chown, path, uid, gid);
}
/**
* security_path_chroot() - Check if changing the root directory is allowed
* @path: directory
*
* Check for permission to change root directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_path_chroot(const struct path *path)
{
return call_int_hook(path_chroot, path);
}
#endif /* CONFIG_SECURITY_PATH */
/**
* security_inode_create() - Check if creating a file is allowed
* @dir: the parent directory
* @dentry: the file being created
* @mode: requested file mode
*
* Check permission to create a regular file.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_create(struct inode *dir, struct dentry *dentry,
umode_t mode)
{
if (unlikely(IS_PRIVATE(dir)))
return 0;
return call_int_hook(inode_create, dir, dentry, mode);
}
EXPORT_SYMBOL_GPL(security_inode_create);
/**
* security_inode_post_create_tmpfile() - Update inode security of new tmpfile
* @idmap: idmap of the mount
* @inode: inode of the new tmpfile
*
* Update inode security data after a tmpfile has been created.
*/
void security_inode_post_create_tmpfile(struct mnt_idmap *idmap,
struct inode *inode)
{
if (unlikely(IS_PRIVATE(inode)))
return;
call_void_hook(inode_post_create_tmpfile, idmap, inode);
}
/**
* security_inode_link() - Check if creating a hard link is allowed
* @old_dentry: existing file
* @dir: new parent directory
* @new_dentry: new link
*
* Check permission before creating a new hard link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry))))
return 0;
return call_int_hook(inode_link, old_dentry, dir, new_dentry);
}
/**
* security_inode_unlink() - Check if removing a hard link is allowed
* @dir: parent directory
* @dentry: file
*
* Check the permission to remove a hard link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_unlink(struct inode *dir, struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_unlink, dir, dentry);
}
/**
* security_inode_symlink() - Check if creating a symbolic link is allowed
* @dir: parent directory
* @dentry: symbolic link
* @old_name: existing filename
*
* Check the permission to create a symbolic link to a file.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_symlink(struct inode *dir, struct dentry *dentry,
const char *old_name)
{
if (unlikely(IS_PRIVATE(dir)))
return 0;
return call_int_hook(inode_symlink, dir, dentry, old_name);
}
/**
* security_inode_mkdir() - Check if creation a new director is allowed
* @dir: parent directory
* @dentry: new directory
* @mode: new directory mode
*
* Check permissions to create a new directory in the existing directory
* associated with inode structure @dir.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
if (unlikely(IS_PRIVATE(dir)))
return 0;
return call_int_hook(inode_mkdir, dir, dentry, mode);
}
EXPORT_SYMBOL_GPL(security_inode_mkdir);
/**
* security_inode_rmdir() - Check if removing a directory is allowed
* @dir: parent directory
* @dentry: directory to be removed
*
* Check the permission to remove a directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_rmdir, dir, dentry);
}
/**
* security_inode_mknod() - Check if creating a special file is allowed
* @dir: parent directory
* @dentry: new file
* @mode: new file mode
* @dev: device number
*
* Check permissions when creating a special file (or a socket or a fifo file
* created via the mknod system call). Note that if mknod operation is being
* done for a regular file, then the create hook will be called and not this
* hook.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t dev)
{
if (unlikely(IS_PRIVATE(dir)))
return 0;
return call_int_hook(inode_mknod, dir, dentry, mode, dev);
}
/**
* security_inode_rename() - Check if renaming a file is allowed
* @old_dir: parent directory of the old file
* @old_dentry: the old file
* @new_dir: parent directory of the new file
* @new_dentry: the new file
* @flags: flags
*
* Check for permission to rename a file or directory.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (unlikely(IS_PRIVATE(d_backing_inode(old_dentry)) ||
(d_is_positive(new_dentry) &&
IS_PRIVATE(d_backing_inode(new_dentry)))))
return 0;
if (flags & RENAME_EXCHANGE) {
int err = call_int_hook(inode_rename, new_dir, new_dentry,
old_dir, old_dentry);
if (err)
return err;
}
return call_int_hook(inode_rename, old_dir, old_dentry,
new_dir, new_dentry);
}
/**
* security_inode_readlink() - Check if reading a symbolic link is allowed
* @dentry: link
*
* Check the permission to read the symbolic link.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_readlink(struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_readlink, dentry);
}
/**
* security_inode_follow_link() - Check if following a symbolic link is allowed
* @dentry: link dentry
* @inode: link inode
* @rcu: true if in RCU-walk mode
*
* Check permission to follow a symbolic link when looking up a pathname. If
* @rcu is true, @inode is not stable.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_follow_link(struct dentry *dentry, struct inode *inode,
bool rcu)
{
if (unlikely(IS_PRIVATE(inode)))
return 0;
return call_int_hook(inode_follow_link, dentry, inode, rcu);
}
/**
* security_inode_permission() - Check if accessing an inode is allowed
* @inode: inode
* @mask: access mask
*
* Check permission before accessing an inode. This hook is called by the
* existing Linux permission function, so a security module can use it to
* provide additional checking for existing Linux permission checks. Notice
* that this hook is called when a file is opened (as well as many other
* operations), whereas the file_security_ops permission hook is called when
* the actual read/write operations are performed.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_permission(struct inode *inode, int mask)
{
if (unlikely(IS_PRIVATE(inode)))
return 0;
return call_int_hook(inode_permission, inode, mask);
}
/**
* security_inode_setattr() - Check if setting file attributes is allowed
* @idmap: idmap of the mount
* @dentry: file
* @attr: new attributes
*
* Check permission before setting file attributes. Note that the kernel call
* to notify_change is performed from several locations, whenever file
* attributes change (such as when a file is truncated, chown/chmod operations,
* transferring disk quotas, etc).
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_setattr(struct mnt_idmap *idmap,
struct dentry *dentry, struct iattr *attr)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_setattr, idmap, dentry, attr);
}
EXPORT_SYMBOL_GPL(security_inode_setattr);
/**
* security_inode_post_setattr() - Update the inode after a setattr operation
* @idmap: idmap of the mount
* @dentry: file
* @ia_valid: file attributes set
*
* Update inode security field after successful setting file attributes.
*/
void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
int ia_valid)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(inode_post_setattr, idmap, dentry, ia_valid);
}
/**
* security_inode_getattr() - Check if getting file attributes is allowed
* @path: file
*
* Check permission before obtaining file attributes.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_getattr(const struct path *path)
{
if (unlikely(IS_PRIVATE(d_backing_inode(path->dentry))))
return 0;
return call_int_hook(inode_getattr, path);
}
/**
* security_inode_setxattr() - Check if setting file xattrs is allowed
* @idmap: idmap of the mount
* @dentry: file
* @name: xattr name
* @value: xattr value
* @size: size of xattr value
* @flags: flags
*
* This hook performs the desired permission checks before setting the extended
* attributes (xattrs) on @dentry. It is important to note that we have some
* additional logic before the main LSM implementation calls to detect if we
* need to perform an additional capability check at the LSM layer.
*
* Normally we enforce a capability check prior to executing the various LSM
* hook implementations, but if a LSM wants to avoid this capability check,
* it can register a 'inode_xattr_skipcap' hook and return a value of 1 for
* xattrs that it wants to avoid the capability check, leaving the LSM fully
* responsible for enforcing the access control for the specific xattr. If all
* of the enabled LSMs refrain from registering a 'inode_xattr_skipcap' hook,
* or return a 0 (the default return value), the capability check is still
* performed. If no 'inode_xattr_skipcap' hooks are registered the capability
* check is performed.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_setxattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
int rc;
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
/* enforce the capability checks at the lsm layer, if needed */
if (!call_int_hook(inode_xattr_skipcap, name)) {
rc = cap_inode_setxattr(dentry, name, value, size, flags);
if (rc)
return rc;
}
return call_int_hook(inode_setxattr, idmap, dentry, name, value, size,
flags);
}
/**
* security_inode_set_acl() - Check if setting posix acls is allowed
* @idmap: idmap of the mount
* @dentry: file
* @acl_name: acl name
* @kacl: acl struct
*
* Check permission before setting posix acls, the posix acls in @kacl are
* identified by @acl_name.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_set_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name,
struct posix_acl *kacl)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_set_acl, idmap, dentry, acl_name, kacl);
}
/**
* security_inode_post_set_acl() - Update inode security from posix acls set
* @dentry: file
* @acl_name: acl name
* @kacl: acl struct
*
* Update inode security data after successfully setting posix acls on @dentry.
* The posix acls in @kacl are identified by @acl_name.
*/
void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name,
struct posix_acl *kacl)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(inode_post_set_acl, dentry, acl_name, kacl);
}
/**
* security_inode_get_acl() - Check if reading posix acls is allowed
* @idmap: idmap of the mount
* @dentry: file
* @acl_name: acl name
*
* Check permission before getting osix acls, the posix acls are identified by
* @acl_name.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_get_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_get_acl, idmap, dentry, acl_name);
}
/**
* security_inode_remove_acl() - Check if removing a posix acl is allowed
* @idmap: idmap of the mount
* @dentry: file
* @acl_name: acl name
*
* Check permission before removing posix acls, the posix acls are identified
* by @acl_name.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_remove_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_remove_acl, idmap, dentry, acl_name);
}
/**
* security_inode_post_remove_acl() - Update inode security after rm posix acls
* @idmap: idmap of the mount
* @dentry: file
* @acl_name: acl name
*
* Update inode security data after successfully removing posix acls on
* @dentry in @idmap. The posix acls are identified by @acl_name.
*/
void security_inode_post_remove_acl(struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(inode_post_remove_acl, idmap, dentry, acl_name);
}
/**
* security_inode_post_setxattr() - Update the inode after a setxattr operation
* @dentry: file
* @name: xattr name
* @value: xattr value
* @size: xattr value size
* @flags: flags
*
* Update inode security field after successful setxattr operation.
*/
void security_inode_post_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(inode_post_setxattr, dentry, name, value, size, flags);
}
/**
* security_inode_getxattr() - Check if xattr access is allowed
* @dentry: file
* @name: xattr name
*
* Check permission before obtaining the extended attributes identified by
* @name for @dentry.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_getxattr(struct dentry *dentry, const char *name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_getxattr, dentry, name);
}
/**
* security_inode_listxattr() - Check if listing xattrs is allowed
* @dentry: file
*
* Check permission before obtaining the list of extended attribute names for
* @dentry.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_listxattr(struct dentry *dentry)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
return call_int_hook(inode_listxattr, dentry);
}
/**
* security_inode_removexattr() - Check if removing an xattr is allowed
* @idmap: idmap of the mount
* @dentry: file
* @name: xattr name
*
* This hook performs the desired permission checks before setting the extended
* attributes (xattrs) on @dentry. It is important to note that we have some
* additional logic before the main LSM implementation calls to detect if we
* need to perform an additional capability check at the LSM layer.
*
* Normally we enforce a capability check prior to executing the various LSM
* hook implementations, but if a LSM wants to avoid this capability check,
* it can register a 'inode_xattr_skipcap' hook and return a value of 1 for
* xattrs that it wants to avoid the capability check, leaving the LSM fully
* responsible for enforcing the access control for the specific xattr. If all
* of the enabled LSMs refrain from registering a 'inode_xattr_skipcap' hook,
* or return a 0 (the default return value), the capability check is still
* performed. If no 'inode_xattr_skipcap' hooks are registered the capability
* check is performed.
*
* Return: Returns 0 if permission is granted.
*/
int security_inode_removexattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name)
{
int rc;
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return 0;
/* enforce the capability checks at the lsm layer, if needed */
if (!call_int_hook(inode_xattr_skipcap, name)) {
rc = cap_inode_removexattr(idmap, dentry, name);
if (rc)
return rc;
}
return call_int_hook(inode_removexattr, idmap, dentry, name);
}
/**
* security_inode_post_removexattr() - Update the inode after a removexattr op
* @dentry: file
* @name: xattr name
*
* Update the inode after a successful removexattr operation.
*/
void security_inode_post_removexattr(struct dentry *dentry, const char *name)
{
if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
return;
call_void_hook(inode_post_removexattr, dentry, name);
}
/**
* security_inode_need_killpriv() - Check if security_inode_killpriv() required
* @dentry: associated dentry
*
* Called when an inode has been changed to determine if
* security_inode_killpriv() should be called.
*
* Return: Return <0 on error to abort the inode change operation, return 0 if
* security_inode_killpriv() does not need to be called, return >0 if
* security_inode_killpriv() does need to be called.
*/
int security_inode_need_killpriv(struct dentry *dentry)
{
return call_int_hook(inode_need_killpriv, dentry);
}
/**
* security_inode_killpriv() - The setuid bit is removed, update LSM state
* @idmap: idmap of the mount
* @dentry: associated dentry
*
* The @dentry's setuid bit is being removed. Remove similar security labels.
* Called with the dentry->d_inode->i_mutex held.
*
* Return: Return 0 on success. If error is returned, then the operation
* causing setuid bit removal is failed.
*/
int security_inode_killpriv(struct mnt_idmap *idmap,
struct dentry *dentry)
{
return call_int_hook(inode_killpriv, idmap, dentry);
}
/**
* security_inode_getsecurity() - Get the xattr security label of an inode
* @idmap: idmap of the mount
* @inode: inode
* @name: xattr name
* @buffer: security label buffer
* @alloc: allocation flag
*
* Retrieve a copy of the extended attribute representation of the security
* label associated with @name for @inode via @buffer. Note that @name is the
* remainder of the attribute name after the security prefix has been removed.
* @alloc is used to specify if the call should return a value via the buffer
* or just the value length.
*
* Return: Returns size of buffer on success.
*/
int security_inode_getsecurity(struct mnt_idmap *idmap,
struct inode *inode, const char *name,
void **buffer, bool alloc)
{
if (unlikely(IS_PRIVATE(inode)))
return LSM_RET_DEFAULT(inode_getsecurity);
return call_int_hook(inode_getsecurity, idmap, inode, name, buffer,
alloc);
}
/**
* security_inode_setsecurity() - Set the xattr security label of an inode
* @inode: inode
* @name: xattr name
* @value: security label
* @size: length of security label
* @flags: flags
*
* Set the security label associated with @name for @inode from the extended
* attribute value @value. @size indicates the size of the @value in bytes.
* @flags may be XATTR_CREATE, XATTR_REPLACE, or 0. Note that @name is the
* remainder of the attribute name after the security. prefix has been removed.
*
* Return: Returns 0 on success.
*/
int security_inode_setsecurity(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
if (unlikely(IS_PRIVATE(inode)))
return LSM_RET_DEFAULT(inode_setsecurity);
return call_int_hook(inode_setsecurity, inode, name, value, size,
flags);
}
/**
* security_inode_listsecurity() - List the xattr security label names
* @inode: inode
* @buffer: buffer
* @buffer_size: size of buffer
*
* Copy the extended attribute names for the security labels associated with
* @inode into @buffer. The maximum size of @buffer is specified by
* @buffer_size. @buffer may be NULL to request the size of the buffer
* required.
*
* Return: Returns number of bytes used/required on success.
*/
int security_inode_listsecurity(struct inode *inode,
char *buffer, size_t buffer_size)
{
if (unlikely(IS_PRIVATE(inode)))
return 0;
return call_int_hook(inode_listsecurity, inode, buffer, buffer_size);
}
EXPORT_SYMBOL(security_inode_listsecurity);
/**
* security_inode_getsecid() - Get an inode's secid
* @inode: inode
* @secid: secid to return
*
* Get the secid associated with the node. In case of failure, @secid will be
* set to zero.
*/
void security_inode_getsecid(struct inode *inode, u32 *secid)
{
call_void_hook(inode_getsecid, inode, secid);
}
/**
* security_inode_copy_up() - Create new creds for an overlayfs copy-up op
* @src: union dentry of copy-up file
* @new: newly created creds
*
* A file is about to be copied up from lower layer to upper layer of overlay
* filesystem. Security module can prepare a set of new creds and modify as
* need be and return new creds. Caller will switch to new creds temporarily to
* create new file and release newly allocated creds.
*
* Return: Returns 0 on success or a negative error code on error.
*/
int security_inode_copy_up(struct dentry *src, struct cred **new)
{
return call_int_hook(inode_copy_up, src, new);
}
EXPORT_SYMBOL(security_inode_copy_up);
/**
* security_inode_copy_up_xattr() - Filter xattrs in an overlayfs copy-up op
* @src: union dentry of copy-up file
* @name: xattr name
*
* Filter the xattrs being copied up when a unioned file is copied up from a
* lower layer to the union/overlay layer. The caller is responsible for
* reading and writing the xattrs, this hook is merely a filter.
*
* Return: Returns 0 to accept the xattr, -ECANCELED to discard the xattr,
* -EOPNOTSUPP if the security module does not know about attribute,
* or a negative error code to abort the copy up.
*/
int security_inode_copy_up_xattr(struct dentry *src, const char *name)
{
int rc;
rc = call_int_hook(inode_copy_up_xattr, src, name);
if (rc != LSM_RET_DEFAULT(inode_copy_up_xattr))
return rc;
return LSM_RET_DEFAULT(inode_copy_up_xattr);
}
EXPORT_SYMBOL(security_inode_copy_up_xattr);
/**
* security_inode_setintegrity() - Set the inode's integrity data
* @inode: inode
* @type: type of integrity, e.g. hash digest, signature, etc
* @value: the integrity value
* @size: size of the integrity value
*
* Register a verified integrity measurement of a inode with LSMs.
* LSMs should free the previously saved data if @value is NULL.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_inode_setintegrity(const struct inode *inode,
enum lsm_integrity_type type, const void *value,
size_t size)
{
return call_int_hook(inode_setintegrity, inode, type, value, size);
}
EXPORT_SYMBOL(security_inode_setintegrity);
/**
* security_kernfs_init_security() - Init LSM context for a kernfs node
* @kn_dir: parent kernfs node
* @kn: the kernfs node to initialize
*
* Initialize the security context of a newly created kernfs node based on its
* own and its parent's attributes.
*
* Return: Returns 0 if permission is granted.
*/
int security_kernfs_init_security(struct kernfs_node *kn_dir,
struct kernfs_node *kn)
{
return call_int_hook(kernfs_init_security, kn_dir, kn);
}
/**
* security_file_permission() - Check file permissions
* @file: file
* @mask: requested permissions
*
* Check file permissions before accessing an open file. This hook is called
* by various operations that read or write files. A security module can use
* this hook to perform additional checking on these operations, e.g. to
* revalidate permissions on use to support privilege bracketing or policy
* changes. Notice that this hook is used when the actual read/write
* operations are performed, whereas the inode_security_ops hook is called when
* a file is opened (as well as many other operations). Although this hook can
* be used to revalidate permissions for various system call operations that
* read or write files, it does not address the revalidation of permissions for
* memory-mapped files. Security modules must handle this separately if they
* need such revalidation.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_permission(struct file *file, int mask)
{
return call_int_hook(file_permission, file, mask);
}
/**
* security_file_alloc() - Allocate and init a file's LSM blob
* @file: the file
*
* Allocate and attach a security structure to the file->f_security field. The
* security field is initialized to NULL when the structure is first created.
*
* Return: Return 0 if the hook is successful and permission is granted.
*/
int security_file_alloc(struct file *file)
{
int rc = lsm_file_alloc(file);
if (rc)
return rc;
rc = call_int_hook(file_alloc_security, file);
if (unlikely(rc))
security_file_free(file);
return rc;
}
/**
* security_file_release() - Perform actions before releasing the file ref
* @file: the file
*
* Perform actions before releasing the last reference to a file.
*/
void security_file_release(struct file *file)
{
call_void_hook(file_release, file);
}
/**
* security_file_free() - Free a file's LSM blob
* @file: the file
*
* Deallocate and free any security structures stored in file->f_security.
*/
void security_file_free(struct file *file)
{
void *blob;
call_void_hook(file_free_security, file);
blob = file->f_security;
if (blob) {
file->f_security = NULL;
kmem_cache_free(lsm_file_cache, blob);
}
}
/**
* security_file_ioctl() - Check if an ioctl is allowed
* @file: associated file
* @cmd: ioctl cmd
* @arg: ioctl arguments
*
* Check permission for an ioctl operation on @file. Note that @arg sometimes
* represents a user space pointer; in other cases, it may be a simple integer
* value. When @arg represents a user space pointer, it should never be used
* by the security module.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
return call_int_hook(file_ioctl, file, cmd, arg);
}
EXPORT_SYMBOL_GPL(security_file_ioctl);
/**
* security_file_ioctl_compat() - Check if an ioctl is allowed in compat mode
* @file: associated file
* @cmd: ioctl cmd
* @arg: ioctl arguments
*
* Compat version of security_file_ioctl() that correctly handles 32-bit
* processes running on 64-bit kernels.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_ioctl_compat(struct file *file, unsigned int cmd,
unsigned long arg)
{
return call_int_hook(file_ioctl_compat, file, cmd, arg);
}
EXPORT_SYMBOL_GPL(security_file_ioctl_compat);
static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
{
/*
* Does we have PROT_READ and does the application expect
* it to imply PROT_EXEC? If not, nothing to talk about...
*/
if ((prot & (PROT_READ | PROT_EXEC)) != PROT_READ)
return prot;
if (!(current->personality & READ_IMPLIES_EXEC))
return prot;
/*
* if that's an anonymous mapping, let it.
*/
if (!file)
return prot | PROT_EXEC;
/*
* ditto if it's not on noexec mount, except that on !MMU we need
* NOMMU_MAP_EXEC (== VM_MAYEXEC) in this case
*/
if (!path_noexec(&file->f_path)) {
#ifndef CONFIG_MMU
if (file->f_op->mmap_capabilities) {
unsigned caps = file->f_op->mmap_capabilities(file);
if (!(caps & NOMMU_MAP_EXEC))
return prot;
}
#endif
return prot | PROT_EXEC;
}
/* anything on noexec mount won't get PROT_EXEC */
return prot;
}
/**
* security_mmap_file() - Check if mmap'ing a file is allowed
* @file: file
* @prot: protection applied by the kernel
* @flags: flags
*
* Check permissions for a mmap operation. The @file may be NULL, e.g. if
* mapping anonymous memory.
*
* Return: Returns 0 if permission is granted.
*/
int security_mmap_file(struct file *file, unsigned long prot,
unsigned long flags)
{
return call_int_hook(mmap_file, file, prot, mmap_prot(file, prot),
flags);
}
/**
* security_mmap_addr() - Check if mmap'ing an address is allowed
* @addr: address
*
* Check permissions for a mmap operation at @addr.
*
* Return: Returns 0 if permission is granted.
*/
int security_mmap_addr(unsigned long addr)
{
return call_int_hook(mmap_addr, addr);
}
/**
* security_file_mprotect() - Check if changing memory protections is allowed
* @vma: memory region
* @reqprot: application requested protection
* @prot: protection applied by the kernel
*
* Check permissions before changing memory access permissions.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
unsigned long prot)
{
return call_int_hook(file_mprotect, vma, reqprot, prot);
}
/**
* security_file_lock() - Check if a file lock is allowed
* @file: file
* @cmd: lock operation (e.g. F_RDLCK, F_WRLCK)
*
* Check permission before performing file locking operations. Note the hook
* mediates both flock and fcntl style locks.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_lock(struct file *file, unsigned int cmd)
{
return call_int_hook(file_lock, file, cmd);
}
/**
* security_file_fcntl() - Check if fcntl() op is allowed
* @file: file
* @cmd: fcntl command
* @arg: command argument
*
* Check permission before allowing the file operation specified by @cmd from
* being performed on the file @file. Note that @arg sometimes represents a
* user space pointer; in other cases, it may be a simple integer value. When
* @arg represents a user space pointer, it should never be used by the
* security module.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
{
return call_int_hook(file_fcntl, file, cmd, arg);
}
/**
* security_file_set_fowner() - Set the file owner info in the LSM blob
* @file: the file
*
* Save owner security information (typically from current->security) in
* file->f_security for later use by the send_sigiotask hook.
*
* This hook is called with file->f_owner.lock held.
*
* Return: Returns 0 on success.
*/
void security_file_set_fowner(struct file *file)
{
call_void_hook(file_set_fowner, file);
}
/**
* security_file_send_sigiotask() - Check if sending SIGIO/SIGURG is allowed
* @tsk: target task
* @fown: signal sender
* @sig: signal to be sent, SIGIO is sent if 0
*
* Check permission for the file owner @fown to send SIGIO or SIGURG to the
* process @tsk. Note that this hook is sometimes called from interrupt. Note
* that the fown_struct, @fown, is never outside the context of a struct file,
* so the file structure (and associated security information) can always be
* obtained: container_of(fown, struct file, f_owner).
*
* Return: Returns 0 if permission is granted.
*/
int security_file_send_sigiotask(struct task_struct *tsk,
struct fown_struct *fown, int sig)
{
return call_int_hook(file_send_sigiotask, tsk, fown, sig);
}
/**
* security_file_receive() - Check if receiving a file via IPC is allowed
* @file: file being received
*
* This hook allows security modules to control the ability of a process to
* receive an open file descriptor via socket IPC.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_receive(struct file *file)
{
return call_int_hook(file_receive, file);
}
/**
* security_file_open() - Save open() time state for late use by the LSM
* @file:
*
* Save open-time permission checking state for later use upon file_permission,
* and recheck access if anything has changed since inode_permission.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_open(struct file *file)
{
int ret;
ret = call_int_hook(file_open, file);
if (ret)
return ret;
return fsnotify_open_perm(file);
}
/**
* security_file_post_open() - Evaluate a file after it has been opened
* @file: the file
* @mask: access mask
*
* Evaluate an opened file and the access mask requested with open(). The hook
* is useful for LSMs that require the file content to be available in order to
* make decisions.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_post_open(struct file *file, int mask)
{
return call_int_hook(file_post_open, file, mask);
}
EXPORT_SYMBOL_GPL(security_file_post_open);
/**
* security_file_truncate() - Check if truncating a file is allowed
* @file: file
*
* Check permission before truncating a file, i.e. using ftruncate. Note that
* truncation permission may also be checked based on the path, using the
* @path_truncate hook.
*
* Return: Returns 0 if permission is granted.
*/
int security_file_truncate(struct file *file)
{
return call_int_hook(file_truncate, file);
}
/**
* security_task_alloc() - Allocate a task's LSM blob
* @task: the task
* @clone_flags: flags indicating what is being shared
*
* Handle allocation of task-related resources.
*
* Return: Returns a zero on success, negative values on failure.
*/
int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
{
int rc = lsm_task_alloc(task);
if (rc)
return rc;
rc = call_int_hook(task_alloc, task, clone_flags);
if (unlikely(rc))
security_task_free(task);
return rc;
}
/**
* security_task_free() - Free a task's LSM blob and related resources
* @task: task
*
* Handle release of task-related resources. Note that this can be called from
* interrupt context.
*/
void security_task_free(struct task_struct *task)
{
call_void_hook(task_free, task);
kfree(task->security);
task->security = NULL;
}
/**
* security_cred_alloc_blank() - Allocate the min memory to allow cred_transfer
* @cred: credentials
* @gfp: gfp flags
*
* Only allocate sufficient memory and attach to @cred such that
* cred_transfer() will not get ENOMEM.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
int rc = lsm_cred_alloc(cred, gfp);
if (rc)
return rc;
rc = call_int_hook(cred_alloc_blank, cred, gfp);
if (unlikely(rc))
security_cred_free(cred);
return rc;
}
/**
* security_cred_free() - Free the cred's LSM blob and associated resources
* @cred: credentials
*
* Deallocate and clear the cred->security field in a set of credentials.
*/
void security_cred_free(struct cred *cred)
{
/*
* There is a failure case in prepare_creds() that
* may result in a call here with ->security being NULL.
*/
if (unlikely(cred->security == NULL))
return;
call_void_hook(cred_free, cred);
kfree(cred->security);
cred->security = NULL;
}
/**
* security_prepare_creds() - Prepare a new set of credentials
* @new: new credentials
* @old: original credentials
* @gfp: gfp flags
*
* Prepare a new set of credentials by copying the data from the old set.
*
* Return: Returns 0 on success, negative values on failure.
*/
int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp)
{
int rc = lsm_cred_alloc(new, gfp);
if (rc)
return rc;
rc = call_int_hook(cred_prepare, new, old, gfp);
if (unlikely(rc))
security_cred_free(new);
return rc;
}
/**
* security_transfer_creds() - Transfer creds
* @new: target credentials
* @old: original credentials
*
* Transfer data from original creds to new creds.
*/
void security_transfer_creds(struct cred *new, const struct cred *old)
{
call_void_hook(cred_transfer, new, old);
}
/**
* security_cred_getsecid() - Get the secid from a set of credentials
* @c: credentials
* @secid: secid value
*
* Retrieve the security identifier of the cred structure @c. In case of
* failure, @secid will be set to zero.
*/
void security_cred_getsecid(const struct cred *c, u32 *secid)
{
*secid = 0;
call_void_hook(cred_getsecid, c, secid);
}
EXPORT_SYMBOL(security_cred_getsecid);
/**
* security_kernel_act_as() - Set the kernel credentials to act as secid
* @new: credentials
* @secid: secid
*
* Set the credentials for a kernel service to act as (subjective context).
* The current task must be the one that nominated @secid.
*
* Return: Returns 0 if successful.
*/
int security_kernel_act_as(struct cred *new, u32 secid)
{
return call_int_hook(kernel_act_as, new, secid);
}
/**
* security_kernel_create_files_as() - Set file creation context using an inode
* @new: target credentials
* @inode: reference inode
*
* Set the file creation context in a set of credentials to be the same as the
* objective context of the specified inode. The current task must be the one
* that nominated @inode.
*
* Return: Returns 0 if successful.
*/
int security_kernel_create_files_as(struct cred *new, struct inode *inode)
{
return call_int_hook(kernel_create_files_as, new, inode);
}
/**
* security_kernel_module_request() - Check if loading a module is allowed
* @kmod_name: module name
*
* Ability to trigger the kernel to automatically upcall to userspace for
* userspace to load a kernel module with the given name.
*
* Return: Returns 0 if successful.
*/
int security_kernel_module_request(char *kmod_name)
{
return call_int_hook(kernel_module_request, kmod_name);
}
/**
* security_kernel_read_file() - Read a file specified by userspace
* @file: file
* @id: file identifier
* @contents: trust if security_kernel_post_read_file() will be called
*
* Read a file specified by userspace.
*
* Return: Returns 0 if permission is granted.
*/
int security_kernel_read_file(struct file *file, enum kernel_read_file_id id,
bool contents)
{
return call_int_hook(kernel_read_file, file, id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_read_file);
/**
* security_kernel_post_read_file() - Read a file specified by userspace
* @file: file
* @buf: file contents
* @size: size of file contents
* @id: file identifier
*
* Read a file specified by userspace. This must be paired with a prior call
* to security_kernel_read_file() call that indicated this hook would also be
* called, see security_kernel_read_file() for more information.
*
* Return: Returns 0 if permission is granted.
*/
int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
enum kernel_read_file_id id)
{
return call_int_hook(kernel_post_read_file, file, buf, size, id);
}
EXPORT_SYMBOL_GPL(security_kernel_post_read_file);
/**
* security_kernel_load_data() - Load data provided by userspace
* @id: data identifier
* @contents: true if security_kernel_post_load_data() will be called
*
* Load data provided by userspace.
*
* Return: Returns 0 if permission is granted.
*/
int security_kernel_load_data(enum kernel_load_data_id id, bool contents)
{
return call_int_hook(kernel_load_data, id, contents);
}
EXPORT_SYMBOL_GPL(security_kernel_load_data);
/**
* security_kernel_post_load_data() - Load userspace data from a non-file source
* @buf: data
* @size: size of data
* @id: data identifier
* @description: text description of data, specific to the id value
*
* Load data provided by a non-file source (usually userspace buffer). This
* must be paired with a prior security_kernel_load_data() call that indicated
* this hook would also be called, see security_kernel_load_data() for more
* information.
*
* Return: Returns 0 if permission is granted.
*/
int security_kernel_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id id,
char *description)
{
return call_int_hook(kernel_post_load_data, buf, size, id, description);
}
EXPORT_SYMBOL_GPL(security_kernel_post_load_data);
/**
* security_task_fix_setuid() - Update LSM with new user id attributes
* @new: updated credentials
* @old: credentials being replaced
* @flags: LSM_SETID_* flag values
*
* Update the module's state after setting one or more of the user identity
* attributes of the current process. The @flags parameter indicates which of
* the set*uid system calls invoked this hook. If @new is the set of
* credentials that will be installed. Modifications should be made to this
* rather than to @current->cred.
*
* Return: Returns 0 on success.
*/
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags)
{
return call_int_hook(task_fix_setuid, new, old, flags);
}
/**
* security_task_fix_setgid() - Update LSM with new group id attributes
* @new: updated credentials
* @old: credentials being replaced
* @flags: LSM_SETID_* flag value
*
* Update the module's state after setting one or more of the group identity
* attributes of the current process. The @flags parameter indicates which of
* the set*gid system calls invoked this hook. @new is the set of credentials
* that will be installed. Modifications should be made to this rather than to
* @current->cred.
*
* Return: Returns 0 on success.
*/
int security_task_fix_setgid(struct cred *new, const struct cred *old,
int flags)
{
return call_int_hook(task_fix_setgid, new, old, flags);
}
/**
* security_task_fix_setgroups() - Update LSM with new supplementary groups
* @new: updated credentials
* @old: credentials being replaced
*
* Update the module's state after setting the supplementary group identity
* attributes of the current process. @new is the set of credentials that will
* be installed. Modifications should be made to this rather than to
* @current->cred.
*
* Return: Returns 0 on success.
*/
int security_task_fix_setgroups(struct cred *new, const struct cred *old)
{
return call_int_hook(task_fix_setgroups, new, old);
}
/**
* security_task_setpgid() - Check if setting the pgid is allowed
* @p: task being modified
* @pgid: new pgid
*
* Check permission before setting the process group identifier of the process
* @p to @pgid.
*
* Return: Returns 0 if permission is granted.
*/
int security_task_setpgid(struct task_struct *p, pid_t pgid)
{
return call_int_hook(task_setpgid, p, pgid);
}
/**
* security_task_getpgid() - Check if getting the pgid is allowed
* @p: task
*
* Check permission before getting the process group identifier of the process
* @p.
*
* Return: Returns 0 if permission is granted.
*/
int security_task_getpgid(struct task_struct *p)
{
return call_int_hook(task_getpgid, p);
}