| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Simplified MAC Kernel (smack) security module |
| * |
| * This file contains the smack hook function implementations. |
| * |
| * Authors: |
| * Casey Schaufler <casey@schaufler-ca.com> |
| * Jarkko Sakkinen <jarkko.sakkinen@intel.com> |
| * |
| * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> |
| * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. |
| * Paul Moore <paul@paul-moore.com> |
| * Copyright (C) 2010 Nokia Corporation |
| * Copyright (C) 2011 Intel Corporation. |
| */ |
| |
| #include <linux/xattr.h> |
| #include <linux/pagemap.h> |
| #include <linux/mount.h> |
| #include <linux/stat.h> |
| #include <linux/kd.h> |
| #include <asm/ioctls.h> |
| #include <linux/ip.h> |
| #include <linux/tcp.h> |
| #include <linux/udp.h> |
| #include <linux/dccp.h> |
| #include <linux/icmpv6.h> |
| #include <linux/slab.h> |
| #include <linux/mutex.h> |
| #include <net/cipso_ipv4.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <linux/audit.h> |
| #include <linux/magic.h> |
| #include <linux/dcache.h> |
| #include <linux/personality.h> |
| #include <linux/msg.h> |
| #include <linux/shm.h> |
| #include <uapi/linux/shm.h> |
| #include <linux/binfmts.h> |
| #include <linux/parser.h> |
| #include <linux/fs_context.h> |
| #include <linux/fs_parser.h> |
| #include <linux/watch_queue.h> |
| #include <linux/io_uring/cmd.h> |
| #include <uapi/linux/lsm.h> |
| #include "smack.h" |
| |
| #define TRANS_TRUE "TRUE" |
| #define TRANS_TRUE_SIZE 4 |
| |
| #define SMK_CONNECTING 0 |
| #define SMK_RECEIVING 1 |
| #define SMK_SENDING 2 |
| |
| /* |
| * Smack uses multiple xattrs. |
| * SMACK64 - for access control, |
| * SMACK64TRANSMUTE - label initialization, |
| * Not saved on files - SMACK64IPIN and SMACK64IPOUT, |
| * Must be set explicitly - SMACK64EXEC and SMACK64MMAP |
| */ |
| #define SMACK_INODE_INIT_XATTRS 2 |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| static DEFINE_MUTEX(smack_ipv6_lock); |
| static LIST_HEAD(smk_ipv6_port_list); |
| #endif |
| struct kmem_cache *smack_rule_cache; |
| int smack_enabled __initdata; |
| |
| #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s} |
| static struct { |
| const char *name; |
| int len; |
| int opt; |
| } smk_mount_opts[] = { |
| {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault}, |
| A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute) |
| }; |
| #undef A |
| |
| static int match_opt_prefix(char *s, int l, char **arg) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) { |
| size_t len = smk_mount_opts[i].len; |
| if (len > l || memcmp(s, smk_mount_opts[i].name, len)) |
| continue; |
| if (len == l || s[len] != '=') |
| continue; |
| *arg = s + len + 1; |
| return smk_mount_opts[i].opt; |
| } |
| return Opt_error; |
| } |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static char *smk_bu_mess[] = { |
| "Bringup Error", /* Unused */ |
| "Bringup", /* SMACK_BRINGUP_ALLOW */ |
| "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */ |
| "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ |
| }; |
| |
| static void smk_bu_mode(int mode, char *s) |
| { |
| int i = 0; |
| |
| if (mode & MAY_READ) |
| s[i++] = 'r'; |
| if (mode & MAY_WRITE) |
| s[i++] = 'w'; |
| if (mode & MAY_EXEC) |
| s[i++] = 'x'; |
| if (mode & MAY_APPEND) |
| s[i++] = 'a'; |
| if (mode & MAY_TRANSMUTE) |
| s[i++] = 't'; |
| if (mode & MAY_LOCK) |
| s[i++] = 'l'; |
| if (i == 0) |
| s[i++] = '-'; |
| s[i] = '\0'; |
| } |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_note(char *note, struct smack_known *sskp, |
| struct smack_known *oskp, int mode, int rc) |
| { |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, oskp->smk_known, acc, note); |
| return 0; |
| } |
| #else |
| #define smk_bu_note(note, sskp, oskp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_current(char *note, struct smack_known *oskp, |
| int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, oskp->smk_known, |
| acc, current->comm, note); |
| return 0; |
| } |
| #else |
| #define smk_bu_current(note, oskp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_task(struct task_struct *otp, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct smack_known *smk_task = smk_of_task_struct_obj(otp); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, smk_task->smk_known, acc, |
| current->comm, otp->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_task(otp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_inode(struct inode *inode, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| if (rc == SMACK_UNCONFINED_SUBJECT && |
| (mode & (MAY_WRITE | MAY_APPEND))) |
| isp->smk_flags |= SMK_INODE_IMPURE; |
| |
| smk_bu_mode(mode, acc); |
| |
| pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_inode(inode, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_file(struct file *file, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file_inode(file); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, file, |
| current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_file(file, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_credfile(const struct cred *cred, struct file *file, |
| int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(cred); |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file_inode(file); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, file, |
| current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_credfile(cred, file, mode, RC) (RC) |
| #endif |
| |
| /** |
| * smk_fetch - Fetch the smack label from a file. |
| * @name: type of the label (attribute) |
| * @ip: a pointer to the inode |
| * @dp: a pointer to the dentry |
| * |
| * Returns a pointer to the master list entry for the Smack label, |
| * NULL if there was no label to fetch, or an error code. |
| */ |
| static struct smack_known *smk_fetch(const char *name, struct inode *ip, |
| struct dentry *dp) |
| { |
| int rc; |
| char *buffer; |
| struct smack_known *skp = NULL; |
| |
| if (!(ip->i_opflags & IOP_XATTR)) |
| return ERR_PTR(-EOPNOTSUPP); |
| |
| buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); |
| if (buffer == NULL) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); |
| if (rc < 0) |
| skp = ERR_PTR(rc); |
| else if (rc == 0) |
| skp = NULL; |
| else |
| skp = smk_import_entry(buffer, rc); |
| |
| kfree(buffer); |
| |
| return skp; |
| } |
| |
| /** |
| * init_inode_smack - initialize an inode security blob |
| * @inode: inode to extract the info from |
| * @skp: a pointer to the Smack label entry to use in the blob |
| * |
| */ |
| static void init_inode_smack(struct inode *inode, struct smack_known *skp) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| |
| isp->smk_inode = skp; |
| isp->smk_flags = 0; |
| } |
| |
| /** |
| * init_task_smack - initialize a task security blob |
| * @tsp: blob to initialize |
| * @task: a pointer to the Smack label for the running task |
| * @forked: a pointer to the Smack label for the forked task |
| * |
| */ |
| static void init_task_smack(struct task_smack *tsp, struct smack_known *task, |
| struct smack_known *forked) |
| { |
| tsp->smk_task = task; |
| tsp->smk_forked = forked; |
| INIT_LIST_HEAD(&tsp->smk_rules); |
| INIT_LIST_HEAD(&tsp->smk_relabel); |
| mutex_init(&tsp->smk_rules_lock); |
| } |
| |
| /** |
| * smk_copy_rules - copy a rule set |
| * @nhead: new rules header pointer |
| * @ohead: old rules header pointer |
| * @gfp: type of the memory for the allocation |
| * |
| * Returns 0 on success, -ENOMEM on error |
| */ |
| static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, |
| gfp_t gfp) |
| { |
| struct smack_rule *nrp; |
| struct smack_rule *orp; |
| int rc = 0; |
| |
| list_for_each_entry_rcu(orp, ohead, list) { |
| nrp = kmem_cache_zalloc(smack_rule_cache, gfp); |
| if (nrp == NULL) { |
| rc = -ENOMEM; |
| break; |
| } |
| *nrp = *orp; |
| list_add_rcu(&nrp->list, nhead); |
| } |
| return rc; |
| } |
| |
| /** |
| * smk_copy_relabel - copy smk_relabel labels list |
| * @nhead: new rules header pointer |
| * @ohead: old rules header pointer |
| * @gfp: type of the memory for the allocation |
| * |
| * Returns 0 on success, -ENOMEM on error |
| */ |
| static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, |
| gfp_t gfp) |
| { |
| struct smack_known_list_elem *nklep; |
| struct smack_known_list_elem *oklep; |
| |
| list_for_each_entry(oklep, ohead, list) { |
| nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); |
| if (nklep == NULL) { |
| smk_destroy_label_list(nhead); |
| return -ENOMEM; |
| } |
| nklep->smk_label = oklep->smk_label; |
| list_add(&nklep->list, nhead); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* |
| * @mode: input mode in form of PTRACE_MODE_* |
| * |
| * Returns a converted MAY_* mode usable by smack rules |
| */ |
| static inline unsigned int smk_ptrace_mode(unsigned int mode) |
| { |
| if (mode & PTRACE_MODE_ATTACH) |
| return MAY_READWRITE; |
| if (mode & PTRACE_MODE_READ) |
| return MAY_READ; |
| |
| return 0; |
| } |
| |
| /** |
| * smk_ptrace_rule_check - helper for ptrace access |
| * @tracer: tracer process |
| * @tracee_known: label entry of the process that's about to be traced |
| * @mode: ptrace attachment mode (PTRACE_MODE_*) |
| * @func: name of the function that called us, used for audit |
| * |
| * Returns 0 on access granted, -error on error |
| */ |
| static int smk_ptrace_rule_check(struct task_struct *tracer, |
| struct smack_known *tracee_known, |
| unsigned int mode, const char *func) |
| { |
| int rc; |
| struct smk_audit_info ad, *saip = NULL; |
| struct task_smack *tsp; |
| struct smack_known *tracer_known; |
| const struct cred *tracercred; |
| |
| if ((mode & PTRACE_MODE_NOAUDIT) == 0) { |
| smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, tracer); |
| saip = &ad; |
| } |
| |
| rcu_read_lock(); |
| tracercred = __task_cred(tracer); |
| tsp = smack_cred(tracercred); |
| tracer_known = smk_of_task(tsp); |
| |
| if ((mode & PTRACE_MODE_ATTACH) && |
| (smack_ptrace_rule == SMACK_PTRACE_EXACT || |
| smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { |
| if (tracer_known->smk_known == tracee_known->smk_known) |
| rc = 0; |
| else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) |
| rc = -EACCES; |
| else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred)) |
| rc = 0; |
| else |
| rc = -EACCES; |
| |
| if (saip) |
| smack_log(tracer_known->smk_known, |
| tracee_known->smk_known, |
| 0, rc, saip); |
| |
| rcu_read_unlock(); |
| return rc; |
| } |
| |
| /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ |
| rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); |
| |
| rcu_read_unlock(); |
| return rc; |
| } |
| |
| /* |
| * LSM hooks. |
| * We he, that is fun! |
| */ |
| |
| /** |
| * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH |
| * @ctp: child task pointer |
| * @mode: ptrace attachment mode (PTRACE_MODE_*) |
| * |
| * Returns 0 if access is OK, an error code otherwise |
| * |
| * Do the capability checks. |
| */ |
| static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) |
| { |
| struct smack_known *skp; |
| |
| skp = smk_of_task_struct_obj(ctp); |
| |
| return smk_ptrace_rule_check(current, skp, mode, __func__); |
| } |
| |
| /** |
| * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME |
| * @ptp: parent task pointer |
| * |
| * Returns 0 if access is OK, an error code otherwise |
| * |
| * Do the capability checks, and require PTRACE_MODE_ATTACH. |
| */ |
| static int smack_ptrace_traceme(struct task_struct *ptp) |
| { |
| struct smack_known *skp; |
| |
| skp = smk_of_task(smack_cred(current_cred())); |
| |
| return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); |
| } |
| |
| /** |
| * smack_syslog - Smack approval on syslog |
| * @typefrom_file: unused |
| * |
| * Returns 0 on success, error code otherwise. |
| */ |
| static int smack_syslog(int typefrom_file) |
| { |
| int rc = 0; |
| struct smack_known *skp = smk_of_current(); |
| |
| if (smack_privileged(CAP_MAC_OVERRIDE)) |
| return 0; |
| |
| if (smack_syslog_label != NULL && smack_syslog_label != skp) |
| rc = -EACCES; |
| |
| return rc; |
| } |
| |
| /* |
| * Superblock Hooks. |
| */ |
| |
| /** |
| * smack_sb_alloc_security - allocate a superblock blob |
| * @sb: the superblock getting the blob |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| */ |
| static int smack_sb_alloc_security(struct super_block *sb) |
| { |
| struct superblock_smack *sbsp = smack_superblock(sb); |
| |
| sbsp->smk_root = &smack_known_floor; |
| sbsp->smk_default = &smack_known_floor; |
| sbsp->smk_floor = &smack_known_floor; |
| sbsp->smk_hat = &smack_known_hat; |
| /* |
| * SMK_SB_INITIALIZED will be zero from kzalloc. |
| */ |
| |
| return 0; |
| } |
| |
| struct smack_mnt_opts { |
| const char *fsdefault; |
| const char *fsfloor; |
| const char *fshat; |
| const char *fsroot; |
| const char *fstransmute; |
| }; |
| |
| static void smack_free_mnt_opts(void *mnt_opts) |
| { |
| kfree(mnt_opts); |
| } |
| |
| static int smack_add_opt(int token, const char *s, void **mnt_opts) |
| { |
| struct smack_mnt_opts *opts = *mnt_opts; |
| struct smack_known *skp; |
| |
| if (!opts) { |
| opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); |
| if (!opts) |
| return -ENOMEM; |
| *mnt_opts = opts; |
| } |
| if (!s) |
| return -ENOMEM; |
| |
| skp = smk_import_entry(s, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| |
| switch (token) { |
| case Opt_fsdefault: |
| if (opts->fsdefault) |
| goto out_opt_err; |
| opts->fsdefault = skp->smk_known; |
| break; |
| case Opt_fsfloor: |
| if (opts->fsfloor) |
| goto out_opt_err; |
| opts->fsfloor = skp->smk_known; |
| break; |
| case Opt_fshat: |
| if (opts->fshat) |
| goto out_opt_err; |
| opts->fshat = skp->smk_known; |
| break; |
| case Opt_fsroot: |
| if (opts->fsroot) |
| goto out_opt_err; |
| opts->fsroot = skp->smk_known; |
| break; |
| case Opt_fstransmute: |
| if (opts->fstransmute) |
| goto out_opt_err; |
| opts->fstransmute = skp->smk_known; |
| break; |
| } |
| return 0; |
| |
| out_opt_err: |
| pr_warn("Smack: duplicate mount options\n"); |
| return -EINVAL; |
| } |
| |
| /** |
| * smack_fs_context_submount - Initialise security data for a filesystem context |
| * @fc: The filesystem context. |
| * @reference: reference superblock |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| */ |
| static int smack_fs_context_submount(struct fs_context *fc, |
| struct super_block *reference) |
| { |
| struct superblock_smack *sbsp; |
| struct smack_mnt_opts *ctx; |
| struct inode_smack *isp; |
| |
| ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); |
| if (!ctx) |
| return -ENOMEM; |
| fc->security = ctx; |
| |
| sbsp = smack_superblock(reference); |
| isp = smack_inode(reference->s_root->d_inode); |
| |
| if (sbsp->smk_default) { |
| ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL); |
| if (!ctx->fsdefault) |
| return -ENOMEM; |
| } |
| |
| if (sbsp->smk_floor) { |
| ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL); |
| if (!ctx->fsfloor) |
| return -ENOMEM; |
| } |
| |
| if (sbsp->smk_hat) { |
| ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL); |
| if (!ctx->fshat) |
| return -ENOMEM; |
| } |
| |
| if (isp->smk_flags & SMK_INODE_TRANSMUTE) { |
| if (sbsp->smk_root) { |
| ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL); |
| if (!ctx->fstransmute) |
| return -ENOMEM; |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * smack_fs_context_dup - Duplicate the security data on fs_context duplication |
| * @fc: The new filesystem context. |
| * @src_fc: The source filesystem context being duplicated. |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| */ |
| static int smack_fs_context_dup(struct fs_context *fc, |
| struct fs_context *src_fc) |
| { |
| struct smack_mnt_opts *dst, *src = src_fc->security; |
| |
| if (!src) |
| return 0; |
| |
| fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); |
| if (!fc->security) |
| return -ENOMEM; |
| |
| dst = fc->security; |
| dst->fsdefault = src->fsdefault; |
| dst->fsfloor = src->fsfloor; |
| dst->fshat = src->fshat; |
| dst->fsroot = src->fsroot; |
| dst->fstransmute = src->fstransmute; |
| |
| return 0; |
| } |
| |
| static const struct fs_parameter_spec smack_fs_parameters[] = { |
| fsparam_string("smackfsdef", Opt_fsdefault), |
| fsparam_string("smackfsdefault", Opt_fsdefault), |
| fsparam_string("smackfsfloor", Opt_fsfloor), |
| fsparam_string("smackfshat", Opt_fshat), |
| fsparam_string("smackfsroot", Opt_fsroot), |
| fsparam_string("smackfstransmute", Opt_fstransmute), |
| {} |
| }; |
| |
| /** |
| * smack_fs_context_parse_param - Parse a single mount parameter |
| * @fc: The new filesystem context being constructed. |
| * @param: The parameter. |
| * |
| * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on |
| * error. |
| */ |
| static int smack_fs_context_parse_param(struct fs_context *fc, |
| struct fs_parameter *param) |
| { |
| struct fs_parse_result result; |
| int opt, rc; |
| |
| opt = fs_parse(fc, smack_fs_parameters, param, &result); |
| if (opt < 0) |
| return opt; |
| |
| rc = smack_add_opt(opt, param->string, &fc->security); |
| if (!rc) |
| param->string = NULL; |
| return rc; |
| } |
| |
| static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts) |
| { |
| char *from = options, *to = options; |
| bool first = true; |
| |
| while (1) { |
| char *next = strchr(from, ','); |
| int token, len, rc; |
| char *arg = NULL; |
| |
| if (next) |
| len = next - from; |
| else |
| len = strlen(from); |
| |
| token = match_opt_prefix(from, len, &arg); |
| if (token != Opt_error) { |
| arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL); |
| rc = smack_add_opt(token, arg, mnt_opts); |
| kfree(arg); |
| if (unlikely(rc)) { |
| if (*mnt_opts) |
| smack_free_mnt_opts(*mnt_opts); |
| *mnt_opts = NULL; |
| return rc; |
| } |
| } else { |
| if (!first) { // copy with preceding comma |
| from--; |
| len++; |
| } |
| if (to != from) |
| memmove(to, from, len); |
| to += len; |
| first = false; |
| } |
| if (!from[len]) |
| break; |
| from += len + 1; |
| } |
| *to = '\0'; |
| return 0; |
| } |
| |
| /** |
| * smack_set_mnt_opts - set Smack specific mount options |
| * @sb: the file system superblock |
| * @mnt_opts: Smack mount options |
| * @kern_flags: mount option from kernel space or user space |
| * @set_kern_flags: where to store converted mount opts |
| * |
| * Returns 0 on success, an error code on failure |
| * |
| * Allow filesystems with binary mount data to explicitly set Smack mount |
| * labels. |
| */ |
| static int smack_set_mnt_opts(struct super_block *sb, |
| void *mnt_opts, |
| unsigned long kern_flags, |
| unsigned long *set_kern_flags) |
| { |
| struct dentry *root = sb->s_root; |
| struct inode *inode = d_backing_inode(root); |
| struct superblock_smack *sp = smack_superblock(sb); |
| struct inode_smack *isp; |
| struct smack_known *skp; |
| struct smack_mnt_opts *opts = mnt_opts; |
| bool transmute = false; |
| |
| if (sp->smk_flags & SMK_SB_INITIALIZED) |
| return 0; |
| |
| if (!smack_privileged(CAP_MAC_ADMIN)) { |
| /* |
| * Unprivileged mounts don't get to specify Smack values. |
| */ |
| if (opts) |
| return -EPERM; |
| /* |
| * Unprivileged mounts get root and default from the caller. |
| */ |
| skp = smk_of_current(); |
| sp->smk_root = skp; |
| sp->smk_default = skp; |
| /* |
| * For a handful of fs types with no user-controlled |
| * backing store it's okay to trust security labels |
| * in the filesystem. The rest are untrusted. |
| */ |
| if (sb->s_user_ns != &init_user_ns && |
| sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && |
| sb->s_magic != RAMFS_MAGIC) { |
| transmute = true; |
| sp->smk_flags |= SMK_SB_UNTRUSTED; |
| } |
| } |
| |
| sp->smk_flags |= SMK_SB_INITIALIZED; |
| |
| if (opts) { |
| if (opts->fsdefault) { |
| skp = smk_import_entry(opts->fsdefault, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_default = skp; |
| } |
| if (opts->fsfloor) { |
| skp = smk_import_entry(opts->fsfloor, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_floor = skp; |
| } |
| if (opts->fshat) { |
| skp = smk_import_entry(opts->fshat, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_hat = skp; |
| } |
| if (opts->fsroot) { |
| skp = smk_import_entry(opts->fsroot, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_root = skp; |
| } |
| if (opts->fstransmute) { |
| skp = smk_import_entry(opts->fstransmute, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_root = skp; |
| transmute = true; |
| } |
| } |
| |
| /* |
| * Initialize the root inode. |
| */ |
| init_inode_smack(inode, sp->smk_root); |
| |
| if (transmute) { |
| isp = smack_inode(inode); |
| isp->smk_flags |= SMK_INODE_TRANSMUTE; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sb_statfs - Smack check on statfs |
| * @dentry: identifies the file system in question |
| * |
| * Returns 0 if current can read the floor of the filesystem, |
| * and error code otherwise |
| */ |
| static int smack_sb_statfs(struct dentry *dentry) |
| { |
| struct superblock_smack *sbp = smack_superblock(dentry->d_sb); |
| int rc; |
| struct smk_audit_info ad; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); |
| rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); |
| return rc; |
| } |
| |
| /* |
| * BPRM hooks |
| */ |
| |
| /** |
| * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec |
| * @bprm: the exec information |
| * |
| * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise |
| */ |
| static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) |
| { |
| struct inode *inode = file_inode(bprm->file); |
| struct task_smack *bsp = smack_cred(bprm->cred); |
| struct inode_smack *isp; |
| struct superblock_smack *sbsp; |
| int rc; |
| |
| isp = smack_inode(inode); |
| if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) |
| return 0; |
| |
| sbsp = smack_superblock(inode->i_sb); |
| if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && |
| isp->smk_task != sbsp->smk_root) |
| return 0; |
| |
| if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
| struct task_struct *tracer; |
| rc = 0; |
| |
| rcu_read_lock(); |
| tracer = ptrace_parent(current); |
| if (likely(tracer != NULL)) |
| rc = smk_ptrace_rule_check(tracer, |
| isp->smk_task, |
| PTRACE_MODE_ATTACH, |
| __func__); |
| rcu_read_unlock(); |
| |
| if (rc != 0) |
| return rc; |
| } |
| if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) |
| return -EPERM; |
| |
| bsp->smk_task = isp->smk_task; |
| bprm->per_clear |= PER_CLEAR_ON_SETID; |
| |
| /* Decide if this is a secure exec. */ |
| if (bsp->smk_task != bsp->smk_forked) |
| bprm->secureexec = 1; |
| |
| return 0; |
| } |
| |
| /* |
| * Inode hooks |
| */ |
| |
| /** |
| * smack_inode_alloc_security - allocate an inode blob |
| * @inode: the inode in need of a blob |
| * |
| * Returns 0 |
| */ |
| static int smack_inode_alloc_security(struct inode *inode) |
| { |
| struct smack_known *skp = smk_of_current(); |
| |
| init_inode_smack(inode, skp); |
| return 0; |
| } |
| |
| /** |
| * smack_inode_init_security - copy out the smack from an inode |
| * @inode: the newly created inode |
| * @dir: containing directory object |
| * @qstr: unused |
| * @xattrs: where to put the attributes |
| * @xattr_count: current number of LSM-provided xattrs (updated) |
| * |
| * Returns 0 if it all works out, -ENOMEM if there's no memory |
| */ |
| static int smack_inode_init_security(struct inode *inode, struct inode *dir, |
| const struct qstr *qstr, |
| struct xattr *xattrs, int *xattr_count) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct inode_smack *issp = smack_inode(inode); |
| struct smack_known *skp = smk_of_task(tsp); |
| struct smack_known *isp = smk_of_inode(inode); |
| struct smack_known *dsp = smk_of_inode(dir); |
| struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count); |
| int may; |
| |
| /* |
| * If equal, transmuting already occurred in |
| * smack_dentry_create_files_as(). No need to check again. |
| */ |
| if (tsp->smk_task != tsp->smk_transmuted) { |
| rcu_read_lock(); |
| may = smk_access_entry(skp->smk_known, dsp->smk_known, |
| &skp->smk_rules); |
| rcu_read_unlock(); |
| } |
| |
| /* |
| * In addition to having smk_task equal to smk_transmuted, |
| * if the access rule allows transmutation and the directory |
| * requests transmutation then by all means transmute. |
| * Mark the inode as changed. |
| */ |
| if ((tsp->smk_task == tsp->smk_transmuted) || |
| (may > 0 && ((may & MAY_TRANSMUTE) != 0) && |
| smk_inode_transmutable(dir))) { |
| struct xattr *xattr_transmute; |
| |
| /* |
| * The caller of smack_dentry_create_files_as() |
| * should have overridden the current cred, so the |
| * inode label was already set correctly in |
| * smack_inode_alloc_security(). |
| */ |
| if (tsp->smk_task != tsp->smk_transmuted) |
| isp = issp->smk_inode = dsp; |
| |
| issp->smk_flags |= SMK_INODE_TRANSMUTE; |
| xattr_transmute = lsm_get_xattr_slot(xattrs, |
| xattr_count); |
| if (xattr_transmute) { |
| xattr_transmute->value = kmemdup(TRANS_TRUE, |
| TRANS_TRUE_SIZE, |
| GFP_NOFS); |
| if (!xattr_transmute->value) |
| return -ENOMEM; |
| |
| xattr_transmute->value_len = TRANS_TRUE_SIZE; |
| xattr_transmute->name = XATTR_SMACK_TRANSMUTE; |
| } |
| } |
| |
| issp->smk_flags |= SMK_INODE_INSTANT; |
| |
| if (xattr) { |
| xattr->value = kstrdup(isp->smk_known, GFP_NOFS); |
| if (!xattr->value) |
| return -ENOMEM; |
| |
| xattr->value_len = strlen(isp->smk_known); |
| xattr->name = XATTR_SMACK_SUFFIX; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smack_inode_link - Smack check on link |
| * @old_dentry: the existing object |
| * @dir: unused |
| * @new_dentry: the new object |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, |
| struct dentry *new_dentry) |
| { |
| struct smack_known *isp; |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); |
| |
| isp = smk_of_inode(d_backing_inode(old_dentry)); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(d_backing_inode(new_dentry)); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_unlink - Smack check on inode deletion |
| * @dir: containing directory object |
| * @dentry: file to unlink |
| * |
| * Returns 0 if current can write the containing directory |
| * and the object, error code otherwise |
| */ |
| static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) |
| { |
| struct inode *ip = d_backing_inode(dentry); |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| /* |
| * You need write access to the thing you're unlinking |
| */ |
| rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); |
| rc = smk_bu_inode(ip, MAY_WRITE, rc); |
| if (rc == 0) { |
| /* |
| * You also need write access to the containing directory |
| */ |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, dir); |
| rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dir, MAY_WRITE, rc); |
| } |
| return rc; |
| } |
| |
| /** |
| * smack_inode_rmdir - Smack check on directory deletion |
| * @dir: containing directory object |
| * @dentry: directory to unlink |
| * |
| * Returns 0 if current can write the containing directory |
| * and the directory, error code otherwise |
| */ |
| static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| /* |
| * You need write access to the thing you're removing |
| */ |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| if (rc == 0) { |
| /* |
| * You also need write access to the containing directory |
| */ |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, dir); |
| rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dir, MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_rename - Smack check on rename |
| * @old_inode: unused |
| * @old_dentry: the old object |
| * @new_inode: unused |
| * @new_dentry: the new object |
| * |
| * Read and write access is required on both the old and |
| * new directories. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_rename(struct inode *old_inode, |
| struct dentry *old_dentry, |
| struct inode *new_inode, |
| struct dentry *new_dentry) |
| { |
| int rc; |
| struct smack_known *isp; |
| struct smk_audit_info ad; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); |
| |
| isp = smk_of_inode(d_backing_inode(old_dentry)); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(d_backing_inode(new_dentry)); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc); |
| } |
| return rc; |
| } |
| |
| /** |
| * smack_inode_permission - Smack version of permission() |
| * @inode: the inode in question |
| * @mask: the access requested |
| * |
| * This is the important Smack hook. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_permission(struct inode *inode, int mask) |
| { |
| struct superblock_smack *sbsp = smack_superblock(inode->i_sb); |
| struct smk_audit_info ad; |
| int no_block = mask & MAY_NOT_BLOCK; |
| int rc; |
| |
| mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
| /* |
| * No permission to check. Existence test. Yup, it's there. |
| */ |
| if (mask == 0) |
| return 0; |
| |
| if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { |
| if (smk_of_inode(inode) != sbsp->smk_root) |
| return -EACCES; |
| } |
| |
| /* May be droppable after audit */ |
| if (no_block) |
| return -ECHILD; |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, inode); |
| rc = smk_curacc(smk_of_inode(inode), mask, &ad); |
| rc = smk_bu_inode(inode, mask, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_setattr - Smack check for setting attributes |
| * @idmap: idmap of the mount |
| * @dentry: the object |
| * @iattr: for the force flag |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, |
| struct iattr *iattr) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| /* |
| * Need to allow for clearing the setuid bit. |
| */ |
| if (iattr->ia_valid & ATTR_FORCE) |
| return 0; |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_getattr - Smack check for getting attributes |
| * @path: path to extract the info from |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_getattr(const struct path *path) |
| { |
| struct smk_audit_info ad; |
| struct inode *inode = d_backing_inode(path->dentry); |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, *path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_inode(inode, MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_setxattr - Smack check for setting xattrs |
| * @idmap: idmap of the mount |
| * @dentry: the object |
| * @name: name of the attribute |
| * @value: value of the attribute |
| * @size: size of the value |
| * @flags: unused |
| * |
| * This protects the Smack attribute explicitly. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_setxattr(struct mnt_idmap *idmap, |
| struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp; |
| int check_priv = 0; |
| int check_import = 0; |
| int check_star = 0; |
| int rc = 0; |
| |
| /* |
| * Check label validity here so import won't fail in post_setxattr |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { |
| check_priv = 1; |
| check_import = 1; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
| strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| check_priv = 1; |
| check_import = 1; |
| check_star = 1; |
| } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
| check_priv = 1; |
| if (!S_ISDIR(d_backing_inode(dentry)->i_mode) || |
| size != TRANS_TRUE_SIZE || |
| strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) |
| rc = -EINVAL; |
| } else |
| rc = cap_inode_setxattr(dentry, name, value, size, flags); |
| |
| if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) |
| rc = -EPERM; |
| |
| if (rc == 0 && check_import) { |
| skp = size ? smk_import_entry(value, size) : NULL; |
| if (IS_ERR(skp)) |
| rc = PTR_ERR(skp); |
| else if (skp == NULL || (check_star && |
| (skp == &smack_known_star || skp == &smack_known_web))) |
| rc = -EINVAL; |
| } |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| if (rc == 0) { |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_post_setxattr - Apply the Smack update approved above |
| * @dentry: object |
| * @name: attribute name |
| * @value: attribute value |
| * @size: attribute size |
| * @flags: unused |
| * |
| * Set the pointer in the inode blob to the entry found |
| * in the master label list. |
| */ |
| static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smack_known *skp; |
| struct inode_smack *isp = smack_inode(d_backing_inode(dentry)); |
| |
| if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
| isp->smk_flags |= SMK_INODE_TRANSMUTE; |
| return; |
| } |
| |
| if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_inode = skp; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_task = skp; |
| } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_mmap = skp; |
| } |
| |
| return; |
| } |
| |
| /** |
| * smack_inode_getxattr - Smack check on getxattr |
| * @dentry: the object |
| * @name: unused |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_getxattr(struct dentry *dentry, const char *name) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_removexattr - Smack check on removexattr |
| * @idmap: idmap of the mount |
| * @dentry: the object |
| * @name: name of the attribute |
| * |
| * Removing the Smack attribute requires CAP_MAC_ADMIN |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_removexattr(struct mnt_idmap *idmap, |
| struct dentry *dentry, const char *name) |
| { |
| struct inode_smack *isp; |
| struct smk_audit_info ad; |
| int rc = 0; |
| |
| if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || |
| strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
| strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || |
| strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| if (!smack_privileged(CAP_MAC_ADMIN)) |
| rc = -EPERM; |
| } else |
| rc = cap_inode_removexattr(idmap, dentry, name); |
| |
| if (rc != 0) |
| return rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| if (rc != 0) |
| return rc; |
| |
| isp = smack_inode(d_backing_inode(dentry)); |
| /* |
| * Don't do anything special for these. |
| * XATTR_NAME_SMACKIPIN |
| * XATTR_NAME_SMACKIPOUT |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
| struct super_block *sbp = dentry->d_sb; |
| struct superblock_smack *sbsp = smack_superblock(sbp); |
| |
| isp->smk_inode = sbsp->smk_default; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) |
| isp->smk_task = NULL; |
| else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) |
| isp->smk_mmap = NULL; |
| else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) |
| isp->smk_flags &= ~SMK_INODE_TRANSMUTE; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_inode_set_acl - Smack check for setting posix acls |
| * @idmap: idmap of the mnt this request came from |
| * @dentry: the object |
| * @acl_name: name of the posix acl |
| * @kacl: the posix acls |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_set_acl(struct mnt_idmap *idmap, |
| struct dentry *dentry, const char *acl_name, |
| struct posix_acl *kacl) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_get_acl - Smack check for getting posix acls |
| * @idmap: idmap of the mnt this request came from |
| * @dentry: the object |
| * @acl_name: name of the posix acl |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_get_acl(struct mnt_idmap *idmap, |
| struct dentry *dentry, const char *acl_name) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_remove_acl - Smack check for getting posix acls |
| * @idmap: idmap of the mnt this request came from |
| * @dentry: the object |
| * @acl_name: name of the posix acl |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_remove_acl(struct mnt_idmap *idmap, |
| struct dentry *dentry, const char *acl_name) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_getsecurity - get smack xattrs |
| * @idmap: idmap of the mount |
| * @inode: the object |
| * @name: attribute name |
| * @buffer: where to put the result |
| * @alloc: duplicate memory |
| * |
| * Returns the size of the attribute or an error code |
| */ |
| static int smack_inode_getsecurity(struct mnt_idmap *idmap, |
| struct inode *inode, const char *name, |
| void **buffer, bool alloc) |
| { |
| struct socket_smack *ssp; |
| struct socket *sock; |
| struct super_block *sbp; |
| struct inode *ip = inode; |
| struct smack_known *isp; |
| struct inode_smack *ispp; |
| size_t label_len; |
| char *label = NULL; |
| |
| if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
| isp = smk_of_inode(inode); |
| } else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { |
| ispp = smack_inode(inode); |
| if (ispp->smk_flags & SMK_INODE_TRANSMUTE) |
| label = TRANS_TRUE; |
| else |
| label = ""; |
| } else { |
| /* |
| * The rest of the Smack xattrs are only on sockets. |
| */ |
| sbp = ip->i_sb; |
| if (sbp->s_magic != SOCKFS_MAGIC) |
| return -EOPNOTSUPP; |
| |
| sock = SOCKET_I(ip); |
| if (sock == NULL || sock->sk == NULL) |
| return -EOPNOTSUPP; |
| |
| ssp = sock->sk->sk_security; |
| |
| if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
| isp = ssp->smk_in; |
| else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) |
| isp = ssp->smk_out; |
| else |
| return -EOPNOTSUPP; |
| } |
| |
| if (!label) |
| label = isp->smk_known; |
| |
| label_len = strlen(label); |
| |
| if (alloc) { |
| *buffer = kstrdup(label, GFP_KERNEL); |
| if (*buffer == NULL) |
| return -ENOMEM; |
| } |
| |
| return label_len; |
| } |
| |
| |
| /** |
| * smack_inode_listsecurity - list the Smack attributes |
| * @inode: the object |
| * @buffer: where they go |
| * @buffer_size: size of buffer |
| */ |
| static int smack_inode_listsecurity(struct inode *inode, char *buffer, |
| size_t buffer_size) |
| { |
| int len = sizeof(XATTR_NAME_SMACK); |
| |
| if (buffer != NULL && len <= buffer_size) |
| memcpy(buffer, XATTR_NAME_SMACK, len); |
| |
| return len; |
| } |
| |
| /** |
| * smack_inode_getsecid - Extract inode's security id |
| * @inode: inode to extract the info from |
| * @secid: where result will be saved |
| */ |
| static void smack_inode_getsecid(struct inode *inode, u32 *secid) |
| { |
| struct smack_known *skp = smk_of_inode(inode); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /* |
| * File Hooks |
| */ |
| |
| /* |
| * There is no smack_file_permission hook |
| * |
| * Should access checks be done on each read or write? |
| * UNICOS and SELinux say yes. |
| * Trusted Solaris, Trusted Irix, and just about everyone else says no. |
| * |
| * I'll say no for now. Smack does not do the frequent |
| * label changing that SELinux does. |
| */ |
| |
| /** |
| * smack_file_alloc_security - assign a file security blob |
| * @file: the object |
| * |
| * The security blob for a file is a pointer to the master |
| * label list, so no allocation is done. |
| * |
| * f_security is the owner security information. It |
| * isn't used on file access checks, it's for send_sigio. |
| * |
| * Returns 0 |
| */ |
| static int smack_file_alloc_security(struct file *file) |
| { |
| struct smack_known **blob = smack_file(file); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smack_file_ioctl - Smack check on ioctls |
| * @file: the object |
| * @cmd: what to do |
| * @arg: unused |
| * |
| * Relies heavily on the correct use of the ioctl command conventions. |
| * |
| * Returns 0 if allowed, error code otherwise |
| */ |
| static int smack_file_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| int rc = 0; |
| struct smk_audit_info ad; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| |
| if (_IOC_DIR(cmd) & _IOC_WRITE) { |
| rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); |
| rc = smk_bu_file(file, MAY_WRITE, rc); |
| } |
| |
| if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { |
| rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_file(file, MAY_READ, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_file_lock - Smack check on file locking |
| * @file: the object |
| * @cmd: unused |
| * |
| * Returns 0 if current has lock access, error code otherwise |
| */ |
| static int smack_file_lock(struct file *file, unsigned int cmd) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); |
| rc = smk_bu_file(file, MAY_LOCK, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_file_fcntl - Smack check on fcntl |
| * @file: the object |
| * @cmd: what action to check |
| * @arg: unused |
| * |
| * Generally these operations are harmless. |
| * File locking operations present an obvious mechanism |
| * for passing information, so they require write access. |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_fcntl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct smk_audit_info ad; |
| int rc = 0; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| switch (cmd) { |
| case F_GETLK: |
| break; |
| case F_SETLK: |
| case F_SETLKW: |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); |
| rc = smk_bu_file(file, MAY_LOCK, rc); |
| break; |
| case F_SETOWN: |
| case F_SETSIG: |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); |
| rc = smk_bu_file(file, MAY_WRITE, rc); |
| break; |
| default: |
| break; |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_mmap_file - Check permissions for a mmap operation. |
| * @file: contains the file structure for file to map (may be NULL). |
| * @reqprot: contains the protection requested by the application. |
| * @prot: contains the protection that will be applied by the kernel. |
| * @flags: contains the operational flags. |
| * |
| * The @file may be NULL, e.g. if mapping anonymous memory. |
| * |
| * Return 0 if permission is granted. |
| */ |
| static int smack_mmap_file(struct file *file, |
| unsigned long reqprot, unsigned long prot, |
| unsigned long flags) |
| { |
| struct smack_known *skp; |
| struct smack_known *mkp; |
| struct smack_rule *srp; |
| struct task_smack *tsp; |
| struct smack_known *okp; |
| struct inode_smack *isp; |
| struct superblock_smack *sbsp; |
| int may; |
| int mmay; |
| int tmay; |
| int rc; |
| |
| if (file == NULL) |
| return 0; |
| |
| if (unlikely(IS_PRIVATE(file_inode(file)))) |
| return 0; |
| |
| isp = smack_inode(file_inode(file)); |
| if (isp->smk_mmap == NULL) |
| return 0; |
| sbsp = smack_superblock(file_inode(file)->i_sb); |
| if (sbsp->smk_flags & SMK_SB_UNTRUSTED && |
| isp->smk_mmap != sbsp->smk_root) |
| return -EACCES; |
| mkp = isp->smk_mmap; |
| |
| tsp = smack_cred(current_cred()); |
| skp = smk_of_current(); |
| rc = 0; |
| |
| rcu_read_lock(); |
| /* |
| * For each Smack rule associated with the subject |
| * label verify that the SMACK64MMAP also has access |
| * to that rule's object label. |
| */ |
| list_for_each_entry_rcu(srp, &skp->smk_rules, list) { |
| okp = srp->smk_object; |
| /* |
| * Matching labels always allows access. |
| */ |
| if (mkp->smk_known == okp->smk_known) |
| continue; |
| /* |
| * If there is a matching local rule take |
| * that into account as well. |
| */ |
| may = smk_access_entry(srp->smk_subject->smk_known, |
| okp->smk_known, |
| &tsp->smk_rules); |
| if (may == -ENOENT) |
| may = srp->smk_access; |
| else |
| may &= srp->smk_access; |
| /* |
| * If may is zero the SMACK64MMAP subject can't |
| * possibly have less access. |
| */ |
| if (may == 0) |
| continue; |
| |
| /* |
| * Fetch the global list entry. |
| * If there isn't one a SMACK64MMAP subject |
| * can't have as much access as current. |
| */ |
| mmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
| &mkp->smk_rules); |
| if (mmay == -ENOENT) { |
| rc = -EACCES; |
| break; |
| } |
| /* |
| * If there is a local entry it modifies the |
| * potential access, too. |
| */ |
| tmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
| &tsp->smk_rules); |
| if (tmay != -ENOENT) |
| mmay &= tmay; |
| |
| /* |
| * If there is any access available to current that is |
| * not available to a SMACK64MMAP subject |
| * deny access. |
| */ |
| if ((may | mmay) != mmay) { |
| rc = -EACCES; |
| break; |
| } |
| } |
| |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_file_set_fowner - set the file security blob value |
| * @file: object in question |
| * |
| */ |
| static void smack_file_set_fowner(struct file *file) |
| { |
| struct smack_known **blob = smack_file(file); |
| |
| *blob = smk_of_current(); |
| } |
| |
| /** |
| * smack_file_send_sigiotask - Smack on sigio |
| * @tsk: The target task |
| * @fown: the object the signal come from |
| * @signum: unused |
| * |
| * Allow a privileged task to get signals even if it shouldn't |
| * |
| * Returns 0 if a subject with the object's smack could |
| * write to the task, an error code otherwise. |
| */ |
| static int smack_file_send_sigiotask(struct task_struct *tsk, |
| struct fown_struct *fown, int signum) |
| { |
| struct smack_known **blob; |
| struct smack_known *skp; |
| struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred)); |
| const struct cred *tcred; |
| struct file *file; |
| int rc; |
| struct smk_audit_info ad; |
| |
| /* |
| * struct fown_struct is never outside the context of a struct file |
| */ |
| file = container_of(fown, struct file, f_owner); |
| |
| /* we don't log here as rc can be overriden */ |
| blob = smack_file(file); |
| skp = *blob; |
| rc = smk_access(skp, tkp, MAY_DELIVER, NULL); |
| rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc); |
| |
| rcu_read_lock(); |
| tcred = __task_cred(tsk); |
| if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred)) |
| rc = 0; |
| rcu_read_unlock(); |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, tsk); |
| smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad); |
| return rc; |
| } |
| |
| /** |
| * smack_file_receive - Smack file receive check |
| * @file: the object |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_receive(struct file *file) |
| { |
| int rc; |
| int may = 0; |
| struct smk_audit_info ad; |
| struct inode *inode = file_inode(file); |
| struct socket *sock; |
| struct task_smack *tsp; |
| struct socket_smack *ssp; |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| |
| if (inode->i_sb->s_magic == SOCKFS_MAGIC) { |
| sock = SOCKET_I(inode); |
| ssp = sock->sk->sk_security; |
| tsp = smack_cred(current_cred()); |
| /* |
| * If the receiving process can't write to the |
| * passed socket or if the passed socket can't |
| * write to the receiving process don't accept |
| * the passed socket. |
| */ |
| rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); |
| rc = smk_bu_file(file, may, rc); |
| if (rc < 0) |
| return rc; |
| rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); |
| rc = smk_bu_file(file, may, rc); |
| return rc; |
| } |
| /* |
| * This code relies on bitmasks. |
| */ |
| if (file->f_mode & FMODE_READ) |
| may = MAY_READ; |
| if (file->f_mode & FMODE_WRITE) |
| may |= MAY_WRITE; |
| |
| rc = smk_curacc(smk_of_inode(inode), may, &ad); |
| rc = smk_bu_file(file, may, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_file_open - Smack dentry open processing |
| * @file: the object |
| * |
| * Set the security blob in the file structure. |
| * Allow the open only if the task has read access. There are |
| * many read operations (e.g. fstat) that you can do with an |
| * fd even if you have the file open write-only. |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_open(struct file *file) |
| { |
| struct task_smack *tsp = smack_cred(file->f_cred); |
| struct inode *inode = file_inode(file); |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); |
| |
| return rc; |
| } |
| |
| /* |
| * Task hooks |
| */ |
| |
| /** |
| * smack_cred_alloc_blank - "allocate" blank task-level security credentials |
| * @cred: the new credentials |
| * @gfp: the atomicity of any memory allocations |
| * |
| * Prepare a blank set of credentials for modification. This must allocate all |
| * the memory the LSM module might require such that cred_transfer() can |
| * complete without error. |
| */ |
| static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) |
| { |
| init_task_smack(smack_cred(cred), NULL, NULL); |
| return 0; |
| } |
| |
| |
| /** |
| * smack_cred_free - "free" task-level security credentials |
| * @cred: the credentials in question |
| * |
| */ |
| static void smack_cred_free(struct cred *cred) |
| { |
| struct task_smack *tsp = smack_cred(cred); |
| struct smack_rule *rp; |
| struct list_head *l; |
| struct list_head *n; |
| |
| smk_destroy_label_list(&tsp->smk_relabel); |
| |
| list_for_each_safe(l, n, &tsp->smk_rules) { |
| rp = list_entry(l, struct smack_rule, list); |
| list_del(&rp->list); |
| kmem_cache_free(smack_rule_cache, rp); |
| } |
| } |
| |
| /** |
| * smack_cred_prepare - prepare new set of credentials for modification |
| * @new: the new credentials |
| * @old: the original credentials |
| * @gfp: the atomicity of any memory allocations |
| * |
| * Prepare a new set of credentials for modification. |
| */ |
| static int smack_cred_prepare(struct cred *new, const struct cred *old, |
| gfp_t gfp) |
| { |
| struct task_smack *old_tsp = smack_cred(old); |
| struct task_smack *new_tsp = smack_cred(new); |
| int rc; |
| |
| init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); |
| |
| rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); |
| if (rc != 0) |
| return rc; |
| |
| rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, |
| gfp); |
| return rc; |
| } |
| |
| /** |
| * smack_cred_transfer - Transfer the old credentials to the new credentials |
| * @new: the new credentials |
| * @old: the original credentials |
| * |
| * Fill in a set of blank credentials from another set of credentials. |
| */ |
| static void smack_cred_transfer(struct cred *new, const struct cred *old) |
| { |
| struct task_smack *old_tsp = smack_cred(old); |
| struct task_smack *new_tsp = smack_cred(new); |
| |
| init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); |
| } |
| |
| /** |
| * smack_cred_getsecid - get the secid corresponding to a creds structure |
| * @cred: the object creds |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the smack label. |
| */ |
| static void smack_cred_getsecid(const struct cred *cred, u32 *secid) |
| { |
| struct smack_known *skp; |
| |
| rcu_read_lock(); |
| skp = smk_of_task(smack_cred(cred)); |
| *secid = skp->smk_secid; |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * smack_kernel_act_as - Set the subjective context in a set of credentials |
| * @new: points to the set of credentials to be modified. |
| * @secid: specifies the security ID to be set |
| * |
| * Set the security data for a kernel service. |
| */ |
| static int smack_kernel_act_as(struct cred *new, u32 secid) |
| { |
| struct task_smack *new_tsp = smack_cred(new); |
| |
| new_tsp->smk_task = smack_from_secid(secid); |
| return 0; |
| } |
| |
| /** |
| * smack_kernel_create_files_as - Set the file creation label in a set of creds |
| * @new: points to the set of credentials to be modified |
| * @inode: points to the inode to use as a reference |
| * |
| * Set the file creation context in a set of credentials to the same |
| * as the objective context of the specified inode |
| */ |
| static int smack_kernel_create_files_as(struct cred *new, |
| struct inode *inode) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| struct task_smack *tsp = smack_cred(new); |
| |
| tsp->smk_forked = isp->smk_inode; |
| tsp->smk_task = tsp->smk_forked; |
| return 0; |
| } |
| |
| /** |
| * smk_curacc_on_task - helper to log task related access |
| * @p: the task object |
| * @access: the access requested |
| * @caller: name of the calling function for audit |
| * |
| * Return 0 if access is permitted |
| */ |
| static int smk_curacc_on_task(struct task_struct *p, int access, |
| const char *caller) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| int rc; |
| |
| smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, p); |
| rc = smk_curacc(skp, access, &ad); |
| rc = smk_bu_task(p, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_task_setpgid - Smack check on setting pgid |
| * @p: the task object |
| * @pgid: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setpgid(struct task_struct *p, pid_t pgid) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getpgid - Smack access check for getpgid |
| * @p: the object task |
| * |
| * Returns 0 if current can read the object task, error code otherwise |
| */ |
| static int smack_task_getpgid(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_getsid - Smack access check for getsid |
| * @p: the object task |
| * |
| * Returns 0 if current can read the object task, error code otherwise |
| */ |
| static int smack_task_getsid(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_current_getsecid_subj - get the subjective secid of the current task |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the task's subjective smack label. |
| */ |
| static void smack_current_getsecid_subj(u32 *secid) |
| { |
| struct smack_known *skp = smk_of_current(); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /** |
| * smack_task_getsecid_obj - get the objective secid of the task |
| * @p: the task |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the task's objective smack label. |
| */ |
| static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) |
| { |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /** |
| * smack_task_setnice - Smack check on setting nice |
| * @p: the task object |
| * @nice: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setnice(struct task_struct *p, int nice) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_setioprio - Smack check on setting ioprio |
| * @p: the task object |
| * @ioprio: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setioprio(struct task_struct *p, int ioprio) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getioprio - Smack check on reading ioprio |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_getioprio(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_setscheduler - Smack check on setting scheduler |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_setscheduler(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getscheduler - Smack check on reading scheduler |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_getscheduler(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_movememory - Smack check on moving memory |
| * @p: the task object |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_movememory(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_kill - Smack check on signal delivery |
| * @p: the task object |
| * @info: unused |
| * @sig: unused |
| * @cred: identifies the cred to use in lieu of current's |
| * |
| * Return 0 if write access is permitted |
| * |
| */ |
| static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, |
| int sig, const struct cred *cred) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp; |
| struct smack_known *tkp = smk_of_task_struct_obj(p); |
| int rc; |
| |
| if (!sig) |
| return 0; /* null signal; existence test */ |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, p); |
| /* |
| * Sending a signal requires that the sender |
| * can write the receiver. |
| */ |
| if (cred == NULL) { |
| rc = smk_curacc(tkp, MAY_DELIVER, &ad); |
| rc = smk_bu_task(p, MAY_DELIVER, rc); |
| return rc; |
| } |
| /* |
| * If the cred isn't NULL we're dealing with some USB IO |
| * specific behavior. This is not clean. For one thing |
| * we can't take privilege into account. |
| */ |
| skp = smk_of_task(smack_cred(cred)); |
| rc = smk_access(skp, tkp, MAY_DELIVER, &ad); |
| rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_task_to_inode - copy task smack into the inode blob |
| * @p: task to copy from |
| * @inode: inode to copy to |
| * |
| * Sets the smack pointer in the inode security blob |
| */ |
| static void smack_task_to_inode(struct task_struct *p, struct inode *inode) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| |
| isp->smk_inode = skp; |
| isp->smk_flags |= SMK_INODE_INSTANT; |
| } |
| |
| /* |
| * Socket hooks. |
| */ |
| |
| /** |
| * smack_sk_alloc_security - Allocate a socket blob |
| * @sk: the socket |
| * @family: unused |
| * @gfp_flags: memory allocation flags |
| * |
| * Assign Smack pointers to current |
| * |
| * Returns 0 on success, -ENOMEM is there's no memory |
| */ |
| static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) |
| { |
| struct smack_known *skp = smk_of_current(); |
| struct socket_smack *ssp; |
| |
| ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); |
| if (ssp == NULL) |
| return -ENOMEM; |
| |
| /* |
| * Sockets created by kernel threads receive web label. |
| */ |
| if (unlikely(current->flags & PF_KTHREAD)) { |
| ssp->smk_in = &smack_known_web; |
| ssp->smk_out = &smack_known_web; |
| } else { |
| ssp->smk_in = skp; |
| ssp->smk_out = skp; |
| } |
| ssp->smk_packet = NULL; |
| |
| sk->sk_security = ssp; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sk_free_security - Free a socket blob |
| * @sk: the socket |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_sk_free_security(struct sock *sk) |
| { |
| #ifdef SMACK_IPV6_PORT_LABELING |
| struct smk_port_label *spp; |
| |
| if (sk->sk_family == PF_INET6) { |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_sock != sk) |
| continue; |
| spp->smk_can_reuse = 1; |
| break; |
| } |
| rcu_read_unlock(); |
| } |
| #endif |
| kfree(sk->sk_security); |
| } |
| |
| /** |
| * smack_sk_clone_security - Copy security context |
| * @sk: the old socket |
| * @newsk: the new socket |
| * |
| * Copy the security context of the old socket pointer to the cloned |
| */ |
| static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk) |
| { |
| struct socket_smack *ssp_old = sk->sk_security; |
| struct socket_smack *ssp_new = newsk->sk_security; |
| |
| *ssp_new = *ssp_old; |
| } |
| |
| /** |
| * smack_ipv4host_label - check host based restrictions |
| * @sip: the object end |
| * |
| * looks for host based access restrictions |
| * |
| * This version will only be appropriate for really small sets of single label |
| * hosts. The caller is responsible for ensuring that the RCU read lock is |
| * taken before calling this function. |
| * |
| * Returns the label of the far end or NULL if it's not special. |
| */ |
| static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) |
| { |
| struct smk_net4addr *snp; |
| struct in_addr *siap = &sip->sin_addr; |
| |
| if (siap->s_addr == 0) |
| return NULL; |
| |
| list_for_each_entry_rcu(snp, &smk_net4addr_list, list) |
| /* |
| * we break after finding the first match because |
| * the list is sorted from longest to shortest mask |
| * so we have found the most specific match |
| */ |
| if (snp->smk_host.s_addr == |
| (siap->s_addr & snp->smk_mask.s_addr)) |
| return snp->smk_label; |
| |
| return NULL; |
| } |
| |
| /* |
| * smk_ipv6_localhost - Check for local ipv6 host address |
| * @sip: the address |
| * |
| * Returns boolean true if this is the localhost address |
| */ |
| static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) |
| { |
| __be16 *be16p = (__be16 *)&sip->sin6_addr; |
| __be32 *be32p = (__be32 *)&sip->sin6_addr; |
| |
| if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && |
| ntohs(be16p[7]) == 1) |
| return true; |
| return false; |
| } |
| |
| /** |
| * smack_ipv6host_label - check host based restrictions |
| * @sip: the object end |
| * |
| * looks for host based access restrictions |
| * |
| * This version will only be appropriate for really small sets of single label |
| * hosts. The caller is responsible for ensuring that the RCU read lock is |
| * taken before calling this function. |
| * |
| * Returns the label of the far end or NULL if it's not special. |
| */ |
| static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) |
| { |
| struct smk_net6addr *snp; |
| struct in6_addr *sap = &sip->sin6_addr; |
| int i; |
| int found = 0; |
| |
| /* |
| * It's local. Don't look for a host label. |
| */ |
| if (smk_ipv6_localhost(sip)) |
| return NULL; |
| |
| list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { |
| /* |
| * If the label is NULL the entry has |
| * been renounced. Ignore it. |
| */ |
| if (snp->smk_label == NULL) |
| continue; |
| /* |
| * we break after finding the first match because |
| * the list is sorted from longest to shortest mask |
| * so we have found the most specific match |
| */ |
| for (found = 1, i = 0; i < 8; i++) { |
| if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != |
| snp->smk_host.s6_addr16[i]) { |
| found = 0; |
| break; |
| } |
| } |
| if (found) |
| return snp->smk_label; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * smack_netlbl_add - Set the secattr on a socket |
| * @sk: the socket |
| * |
| * Attach the outbound smack value (smk_out) to the socket. |
| * |
| * Returns 0 on success or an error code |
| */ |
| static int smack_netlbl_add(struct sock *sk) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp = ssp->smk_out; |
| int rc; |
| |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| |
| rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel, |
| netlbl_sk_lock_check(sk)); |
| switch (rc) { |
| case 0: |
| ssp->smk_state = SMK_NETLBL_LABELED; |
| break; |
| case -EDESTADDRREQ: |
| ssp->smk_state = SMK_NETLBL_REQSKB; |
| rc = 0; |
| break; |
| } |
| |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_netlbl_delete - Remove the secattr from a socket |
| * @sk: the socket |
| * |
| * Remove the outbound smack value from a socket |
| */ |
| static void smack_netlbl_delete(struct sock *sk) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| |
| /* |
| * Take the label off the socket if one is set. |
| */ |
| if (ssp->smk_state != SMK_NETLBL_LABELED) |
| return; |
| |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| netlbl_sock_delattr(sk); |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| ssp->smk_state = SMK_NETLBL_UNLABELED; |
| } |
| |
| /** |
| * smk_ipv4_check - Perform IPv4 host access checks |
| * @sk: the socket |
| * @sap: the destination address |
| * |
| * Set the correct secattr for the given socket based on the destination |
| * address and perform any outbound access checks needed. |
| * |
| * Returns 0 on success or an error code. |
| * |
| */ |
| static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) |
| { |
| struct smack_known *skp; |
| int rc = 0; |
| struct smack_known *hkp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smk_audit_info ad; |
| |
| rcu_read_lock(); |
| hkp = smack_ipv4host_label(sap); |
| if (hkp != NULL) { |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = sap->sin_family; |
| ad.a.u.net->dport = sap->sin_port; |
| ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; |
| #endif |
| skp = ssp->smk_out; |
| rc = smk_access(skp, hkp, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); |
| /* |
| * Clear the socket netlabel if it's set. |
| */ |
| if (!rc) |
| smack_netlbl_delete(sk); |
| } |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * smk_ipv6_check - check Smack access |
| * @subject: subject Smack label |
| * @object: object Smack label |
| * @address: address |
| * @act: the action being taken |
| * |
| * Check an IPv6 access |
| */ |
| static int smk_ipv6_check(struct smack_known *subject, |
| struct smack_known *object, |
| struct sockaddr_in6 *address, int act) |
| { |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = PF_INET6; |
| ad.a.u.net->dport = address->sin6_port; |
| if (act == SMK_RECEIVING) |
| ad.a.u.net->v6info.saddr = address->sin6_addr; |
| else |
| ad.a.u.net->v6info.daddr = address->sin6_addr; |
| #endif |
| rc = smk_access(subject, object, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc); |
| return rc; |
| } |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| /** |
| * smk_ipv6_port_label - Smack port access table management |
| * @sock: socket |
| * @address: address |
| * |
| * Create or update the port list entry |
| */ |
| static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) |
| { |
| struct sock *sk = sock->sk; |
| struct sockaddr_in6 *addr6; |
| struct socket_smack *ssp = sock->sk->sk_security; |
| struct smk_port_label *spp; |
| unsigned short port = 0; |
| |
| if (address == NULL) { |
| /* |
| * This operation is changing the Smack information |
| * on the bound socket. Take the changes to the port |
| * as well. |
| */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (sk != spp->smk_sock) |
| continue; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| rcu_read_unlock(); |
| return; |
| } |
| /* |
| * A NULL address is only used for updating existing |
| * bound entries. If there isn't one, it's OK. |
| */ |
| rcu_read_unlock(); |
| return; |
| } |
| |
| addr6 = (struct sockaddr_in6 *)address; |
| port = ntohs(addr6->sin6_port); |
| /* |
| * This is a special case that is safely ignored. |
| */ |
| if (port == 0) |
| return; |
| |
| /* |
| * Look for an existing port list entry. |
| * This is an indication that a port is getting reused. |
| */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port || spp->smk_sock_type != sock->type) |
| continue; |
| if (spp->smk_can_reuse != 1) { |
| rcu_read_unlock(); |
| return; |
| } |
| spp->smk_port = port; |
| spp->smk_sock = sk; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| spp->smk_can_reuse = 0; |
| rcu_read_unlock(); |
| return; |
| } |
| rcu_read_unlock(); |
| /* |
| * A new port entry is required. |
| */ |
| spp = kzalloc(sizeof(*spp), GFP_KERNEL); |
| if (spp == NULL) |
| return; |
| |
| spp->smk_port = port; |
| spp->smk_sock = sk; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| spp->smk_sock_type = sock->type; |
| spp->smk_can_reuse = 0; |
| |
| mutex_lock(&smack_ipv6_lock); |
| list_add_rcu(&spp->list, &smk_ipv6_port_list); |
| mutex_unlock(&smack_ipv6_lock); |
| return; |
| } |
| |
| /** |
| * smk_ipv6_port_check - check Smack port access |
| * @sk: socket |
| * @address: address |
| * @act: the action being taken |
| * |
| * Create or update the port list entry |
| */ |
| static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, |
| int act) |
| { |
| struct smk_port_label *spp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp = NULL; |
| unsigned short port; |
| struct smack_known *object; |
| |
| if (act == SMK_RECEIVING) { |
| skp = smack_ipv6host_label(address); |
| object = ssp->smk_in; |
| } else { |
| skp = ssp->smk_out; |
| object = smack_ipv6host_label(address); |
| } |
| |
| /* |
| * The other end is a single label host. |
| */ |
| if (skp != NULL && object != NULL) |
| return smk_ipv6_check(skp, object, address, act); |
| if (skp == NULL) |
| skp = smack_net_ambient; |
| if (object == NULL) |
| object = smack_net_ambient; |
| |
| /* |
| * It's remote, so port lookup does no good. |
| */ |
| if (!smk_ipv6_localhost(address)) |
| return smk_ipv6_check(skp, object, address, act); |
| |
| /* |
| * It's local so the send check has to have passed. |
| */ |
| if (act == SMK_RECEIVING) |
| return 0; |
| |
| port = ntohs(address->sin6_port); |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) |
| continue; |
| object = spp->smk_in; |
| if (act == SMK_CONNECTING) |
| ssp->smk_packet = spp->smk_out; |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return smk_ipv6_check(skp, object, address, act); |
| } |
| #endif |
| |
| /** |
| * smack_inode_setsecurity - set smack xattrs |
| * @inode: the object |
| * @name: attribute name |
| * @value: attribute value |
| * @size: size of the attribute |
| * @flags: unused |
| * |
| * Sets the named attribute in the appropriate blob |
| * |
| * Returns 0 on success, or an error code |
| */ |
| static int smack_inode_setsecurity(struct inode *inode, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smack_known *skp; |
| struct inode_smack *nsp = smack_inode(inode); |
| struct socket_smack *ssp; |
| struct socket *sock; |
| int rc = 0; |
| |
| if (value == NULL || size > SMK_LONGLABEL || size == 0) |
| return -EINVAL; |
| |
| if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) { |
| if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE || |
| strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) |
| return -EINVAL; |
| |
| nsp->smk_flags |= SMK_INODE_TRANSMUTE; |
| return 0; |
| } |
| |
| skp = smk_import_entry(value, size); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| |
| if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
| nsp->smk_inode = skp; |
| nsp->smk_flags |= SMK_INODE_INSTANT; |
| return 0; |
| } |
| /* |
| * The rest of the Smack xattrs are only on sockets. |
| */ |
| if (inode->i_sb->s_magic != SOCKFS_MAGIC) |
| return -EOPNOTSUPP; |
| |
| sock = SOCKET_I(inode); |
| if (sock == NULL || sock->sk == NULL) |
| return -EOPNOTSUPP; |
| |
| ssp = sock->sk->sk_security; |
| |
| if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
| ssp->smk_in = skp; |
| else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { |
| ssp->smk_out = skp; |
| if (sock->sk->sk_family == PF_INET) { |
| rc = smack_netlbl_add(sock->sk); |
| if (rc != 0) |
| printk(KERN_WARNING |
| "Smack: \"%s\" netlbl error %d.\n", |
| __func__, -rc); |
| } |
| } else |
| return -EOPNOTSUPP; |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| if (sock->sk->sk_family == PF_INET6) |
| smk_ipv6_port_label(sock, NULL); |
| #endif |
| |
| return 0; |
| } |
| |
| /** |
| * smack_socket_post_create - finish socket setup |
| * @sock: the socket |
| * @family: protocol family |
| * @type: unused |
| * @protocol: unused |
| * @kern: unused |
| * |
| * Sets the netlabel information on the socket |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_post_create(struct socket *sock, int family, |
| int type, int protocol, int kern) |
| { |
| struct socket_smack *ssp; |
| |
| if (sock->sk == NULL) |
| return 0; |
| |
| /* |
| * Sockets created by kernel threads receive web label. |
| */ |
| if (unlikely(current->flags & PF_KTHREAD)) { |
| ssp = sock->sk->sk_security; |
| ssp->smk_in = &smack_known_web; |
| ssp->smk_out = &smack_known_web; |
| } |
| |
| if (family != PF_INET) |
| return 0; |
| /* |
| * Set the outbound netlbl. |
| */ |
| return smack_netlbl_add(sock->sk); |
| } |
| |
| /** |
| * smack_socket_socketpair - create socket pair |
| * @socka: one socket |
| * @sockb: another socket |
| * |
| * Cross reference the peer labels for SO_PEERSEC |
| * |
| * Returns 0 |
| */ |
| static int smack_socket_socketpair(struct socket *socka, |
| struct socket *sockb) |
| { |
| struct socket_smack *asp = socka->sk->sk_security; |
| struct socket_smack *bsp = sockb->sk->sk_security; |
| |
| asp->smk_packet = bsp->smk_out; |
| bsp->smk_packet = asp->smk_out; |
| |
| return 0; |
| } |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| /** |
| * smack_socket_bind - record port binding information. |
| * @sock: the socket |
| * @address: the port address |
| * @addrlen: size of the address |
| * |
| * Records the label bound to a port. |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_bind(struct socket *sock, struct sockaddr *address, |
| int addrlen) |
| { |
| if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) { |
| if (addrlen < SIN6_LEN_RFC2133 || |
| address->sa_family != AF_INET6) |
| return -EINVAL; |
| smk_ipv6_port_label(sock, address); |
| } |
| return 0; |
| } |
| #endif /* SMACK_IPV6_PORT_LABELING */ |
| |
| /** |
| * smack_socket_connect - connect access check |
| * @sock: the socket |
| * @sap: the other end |
| * @addrlen: size of sap |
| * |
| * Verifies that a connection may be possible |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, |
| int addrlen) |
| { |
| int rc = 0; |
| |
| if (sock->sk == NULL) |
| return 0; |
| if (sock->sk->sk_family != PF_INET && |
| (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) |
| return 0; |
| if (addrlen < offsetofend(struct sockaddr, sa_family)) |
| return 0; |
| if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { |
| struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; |
| struct smack_known *rsp = NULL; |
| |
| if (addrlen < SIN6_LEN_RFC2133) |
| return 0; |
| if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) |
| rsp = smack_ipv6host_label(sip); |
| if (rsp != NULL) { |
| struct socket_smack *ssp = sock->sk->sk_security; |
| |
| rc = smk_ipv6_check(ssp->smk_out, rsp, sip, |
| SMK_CONNECTING); |
| } |
| #ifdef SMACK_IPV6_PORT_LABELING |
| rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); |
| #endif |
| |
| return rc; |
| } |
| if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) |
| return 0; |
| rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap); |
| return rc; |
| } |
| |
| /** |
| * smack_flags_to_may - convert S_ to MAY_ values |
| * @flags: the S_ value |
| * |
| * Returns the equivalent MAY_ value |
| */ |
| static int smack_flags_to_may(int flags) |
| { |
| int may = 0; |
| |
| if (flags & S_IRUGO) |
| may |= MAY_READ; |
| if (flags & S_IWUGO) |
| may |= MAY_WRITE; |
| if (flags & S_IXUGO) |
| may |= MAY_EXEC; |
| |
| return may; |
| } |
| |
| /** |
| * smack_msg_msg_alloc_security - Set the security blob for msg_msg |
| * @msg: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_msg_msg_alloc_security(struct msg_msg *msg) |
| { |
| struct smack_known **blob = smack_msg_msg(msg); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smack_of_ipc - the smack pointer for the ipc |
| * @isp: the object |
| * |
| * Returns a pointer to the smack value |
| */ |
| static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) |
| { |
| struct smack_known **blob = smack_ipc(isp); |
| |
| return *blob; |
| } |
| |
| /** |
| * smack_ipc_alloc_security - Set the security blob for ipc |
| * @isp: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) |
| { |
| struct smack_known **blob = smack_ipc(isp); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smk_curacc_shm : check if current has access on shm |
| * @isp : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) |
| { |
| struct smack_known *ssp = smack_of_ipc(isp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = isp->id; |
| #endif |
| rc = smk_curacc(ssp, access, &ad); |
| rc = smk_bu_current("shm", ssp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_shm_associate - Smack access check for shm |
| * @isp: the object |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smack_shm_shmctl - Smack access check for shm |
| * @isp: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case IPC_STAT: |
| case SHM_STAT: |
| case SHM_STAT_ANY: |
| may = MAY_READ; |
| break; |
| case IPC_SET: |
| case SHM_LOCK: |
| case SHM_UNLOCK: |
| case IPC_RMID: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case SHM_INFO: |
| /* |
| * System level information. |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smack_shm_shmat - Smack access for shmat |
| * @isp: the object |
| * @shmaddr: unused |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr, |
| int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smk_curacc_sem : check if current has access on sem |
| * @isp : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) |
| { |
| struct smack_known *ssp = smack_of_ipc(isp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = isp->id; |
| #endif |
| rc = smk_curacc(ssp, access, &ad); |
| rc = smk_bu_current("sem", ssp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_sem_associate - Smack access check for sem |
| * @isp: the object |
| * @semflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(semflg); |
| return smk_curacc_sem(isp, may); |
| } |
| |
| /** |
| * smack_sem_semctl - Smack access check for sem |
| * @isp: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case GETPID: |
| case GETNCNT: |
| case GETZCNT: |
| case GETVAL: |
| case GETALL: |
| case IPC_STAT: |
| case SEM_STAT: |
| case SEM_STAT_ANY: |
| may = MAY_READ; |
| break; |
| case SETVAL: |
| case SETALL: |
| case IPC_RMID: |
| case IPC_SET: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case SEM_INFO: |
| /* |
| * System level information |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| |
|