| /* |
| * 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. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2, |
| * as published by the Free Software Foundation. |
| */ |
| |
| #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/slab.h> |
| #include <linux/mutex.h> |
| #include <linux/pipe_fs_i.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 <linux/binfmts.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 |
| |
| #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) |
| LIST_HEAD(smk_ipv6_port_list); |
| #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */ |
| static struct kmem_cache *smack_inode_cache; |
| int smack_enabled; |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| 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; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) %s\n", |
| 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 = current_security(); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) %s %s\n", |
| 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 = current_security(); |
| struct smack_known *smk_task = smk_of_task_struct(otp); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) %s to %s\n", |
| 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 = current_security(); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n", |
| tsp->smk_task->smk_known, smk_of_inode(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 = current_security(); |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file_inode(file); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n", |
| 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 = cred->security; |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file->f_inode; |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n", |
| 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 |
| * or NULL if there was no label to fetch. |
| */ |
| 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_op->getxattr == NULL) |
| return NULL; |
| |
| buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL); |
| if (buffer == NULL) |
| return NULL; |
| |
| rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL); |
| if (rc > 0) |
| skp = smk_import_entry(buffer, rc); |
| |
| kfree(buffer); |
| |
| return skp; |
| } |
| |
| /** |
| * new_inode_smack - allocate an inode security blob |
| * @skp: a pointer to the Smack label entry to use in the blob |
| * |
| * Returns the new blob or NULL if there's no memory available |
| */ |
| struct inode_smack *new_inode_smack(struct smack_known *skp) |
| { |
| struct inode_smack *isp; |
| |
| isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS); |
| if (isp == NULL) |
| return NULL; |
| |
| isp->smk_inode = skp; |
| isp->smk_flags = 0; |
| mutex_init(&isp->smk_lock); |
| |
| return isp; |
| } |
| |
| /** |
| * new_task_smack - allocate a task security blob |
| * @task: a pointer to the Smack label for the running task |
| * @forked: a pointer to the Smack label for the forked task |
| * @gfp: type of the memory for the allocation |
| * |
| * Returns the new blob or NULL if there's no memory available |
| */ |
| static struct task_smack *new_task_smack(struct smack_known *task, |
| struct smack_known *forked, gfp_t gfp) |
| { |
| struct task_smack *tsp; |
| |
| tsp = kzalloc(sizeof(struct task_smack), gfp); |
| if (tsp == NULL) |
| return NULL; |
| |
| tsp->smk_task = task; |
| tsp->smk_forked = forked; |
| INIT_LIST_HEAD(&tsp->smk_rules); |
| mutex_init(&tsp->smk_rules_lock); |
| |
| return tsp; |
| } |
| |
| /** |
| * 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; |
| |
| INIT_LIST_HEAD(nhead); |
| |
| list_for_each_entry_rcu(orp, ohead, list) { |
| nrp = kzalloc(sizeof(struct smack_rule), gfp); |
| if (nrp == NULL) { |
| rc = -ENOMEM; |
| break; |
| } |
| *nrp = *orp; |
| list_add_rcu(&nrp->list, nhead); |
| } |
| return rc; |
| } |
| |
| /** |
| * 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) |
| { |
| switch (mode) { |
| case PTRACE_MODE_READ: |
| return MAY_READ; |
| case PTRACE_MODE_ATTACH: |
| return MAY_READWRITE; |
| } |
| |
| 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; |
| |
| 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(); |
| tsp = __task_cred(tracer)->security; |
| 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 (capable(CAP_SYS_PTRACE)) |
| 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) |
| { |
| int rc; |
| struct smack_known *skp; |
| |
| rc = cap_ptrace_access_check(ctp, mode); |
| if (rc != 0) |
| return rc; |
| |
| skp = smk_of_task_struct(ctp); |
| |
| rc = smk_ptrace_rule_check(current, skp, mode, __func__); |
| return rc; |
| } |
| |
| /** |
| * 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) |
| { |
| int rc; |
| struct smack_known *skp; |
| |
| rc = cap_ptrace_traceme(ptp); |
| if (rc != 0) |
| return rc; |
| |
| skp = smk_of_task(current_security()); |
| |
| rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); |
| return rc; |
| } |
| |
| /** |
| * smack_syslog - Smack approval on syslog |
| * @type: message type |
| * |
| * 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; |
| |
| sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); |
| |
| if (sbsp == NULL) |
| return -ENOMEM; |
| |
| 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_initialized will be zero from kzalloc. |
| */ |
| sb->s_security = sbsp; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sb_free_security - free a superblock blob |
| * @sb: the superblock getting the blob |
| * |
| */ |
| static void smack_sb_free_security(struct super_block *sb) |
| { |
| kfree(sb->s_security); |
| sb->s_security = NULL; |
| } |
| |
| /** |
| * smack_sb_copy_data - copy mount options data for processing |
| * @orig: where to start |
| * @smackopts: mount options string |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| * |
| * Copy the Smack specific mount options out of the mount |
| * options list. |
| */ |
| static int smack_sb_copy_data(char *orig, char *smackopts) |
| { |
| char *cp, *commap, *otheropts, *dp; |
| |
| otheropts = (char *)get_zeroed_page(GFP_KERNEL); |
| if (otheropts == NULL) |
| return -ENOMEM; |
| |
| for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { |
| if (strstr(cp, SMK_FSDEFAULT) == cp) |
| dp = smackopts; |
| else if (strstr(cp, SMK_FSFLOOR) == cp) |
| dp = smackopts; |
| else if (strstr(cp, SMK_FSHAT) == cp) |
| dp = smackopts; |
| else if (strstr(cp, SMK_FSROOT) == cp) |
| dp = smackopts; |
| else if (strstr(cp, SMK_FSTRANS) == cp) |
| dp = smackopts; |
| else |
| dp = otheropts; |
| |
| commap = strchr(cp, ','); |
| if (commap != NULL) |
| *commap = '\0'; |
| |
| if (*dp != '\0') |
| strcat(dp, ","); |
| strcat(dp, cp); |
| } |
| |
| strcpy(orig, otheropts); |
| free_page((unsigned long)otheropts); |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sb_kern_mount - Smack specific mount processing |
| * @sb: the file system superblock |
| * @flags: the mount flags |
| * @data: the smack mount options |
| * |
| * Returns 0 on success, an error code on failure |
| */ |
| static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) |
| { |
| struct dentry *root = sb->s_root; |
| struct inode *inode = root->d_inode; |
| struct superblock_smack *sp = sb->s_security; |
| struct inode_smack *isp; |
| struct smack_known *skp; |
| char *op; |
| char *commap; |
| int transmute = 0; |
| int specified = 0; |
| |
| if (sp->smk_initialized) |
| return 0; |
| |
| sp->smk_initialized = 1; |
| |
| for (op = data; op != NULL; op = commap) { |
| commap = strchr(op, ','); |
| if (commap != NULL) |
| *commap++ = '\0'; |
| |
| if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { |
| op += strlen(SMK_FSHAT); |
| skp = smk_import_entry(op, 0); |
| if (skp != NULL) { |
| sp->smk_hat = skp; |
| specified = 1; |
| } |
| } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { |
| op += strlen(SMK_FSFLOOR); |
| skp = smk_import_entry(op, 0); |
| if (skp != NULL) { |
| sp->smk_floor = skp; |
| specified = 1; |
| } |
| } else if (strncmp(op, SMK_FSDEFAULT, |
| strlen(SMK_FSDEFAULT)) == 0) { |
| op += strlen(SMK_FSDEFAULT); |
| skp = smk_import_entry(op, 0); |
| if (skp != NULL) { |
| sp->smk_default = skp; |
| specified = 1; |
| } |
| } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { |
| op += strlen(SMK_FSROOT); |
| skp = smk_import_entry(op, 0); |
| if (skp != NULL) { |
| sp->smk_root = skp; |
| specified = 1; |
| } |
| } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) { |
| op += strlen(SMK_FSTRANS); |
| skp = smk_import_entry(op, 0); |
| if (skp != NULL) { |
| sp->smk_root = skp; |
| transmute = 1; |
| specified = 1; |
| } |
| } |
| } |
| |
| if (!smack_privileged(CAP_MAC_ADMIN)) { |
| /* |
| * Unprivileged mounts don't get to specify Smack values. |
| */ |
| if (specified) |
| return -EPERM; |
| /* |
| * Unprivileged mounts get root and default from the caller. |
| */ |
| skp = smk_of_current(); |
| sp->smk_root = skp; |
| sp->smk_default = skp; |
| } |
| /* |
| * Initialize the root inode. |
| */ |
| isp = inode->i_security; |
| if (isp == NULL) { |
| isp = new_inode_smack(sp->smk_root); |
| if (isp == NULL) |
| return -ENOMEM; |
| inode->i_security = isp; |
| } else |
| isp->smk_inode = sp->smk_root; |
| |
| if (transmute) |
| 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 = dentry->d_sb->s_security; |
| 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_set_creds - set creds for exec |
| * @bprm: the exec information |
| * |
| * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise |
| */ |
| static int smack_bprm_set_creds(struct linux_binprm *bprm) |
| { |
| struct inode *inode = file_inode(bprm->file); |
| struct task_smack *bsp = bprm->cred->security; |
| struct inode_smack *isp; |
| int rc; |
| |
| rc = cap_bprm_set_creds(bprm); |
| if (rc != 0) |
| return rc; |
| |
| if (bprm->cred_prepared) |
| return 0; |
| |
| isp = inode->i_security; |
| if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) |
| return 0; |
| |
| if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { |
| 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; |
| } else if (bprm->unsafe) |
| return -EPERM; |
| |
| bsp->smk_task = isp->smk_task; |
| bprm->per_clear |= PER_CLEAR_ON_SETID; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_bprm_committing_creds - Prepare to install the new credentials |
| * from bprm. |
| * |
| * @bprm: binprm for exec |
| */ |
| static void smack_bprm_committing_creds(struct linux_binprm *bprm) |
| { |
| struct task_smack *bsp = bprm->cred->security; |
| |
| if (bsp->smk_task != bsp->smk_forked) |
| current->pdeath_signal = 0; |
| } |
| |
| /** |
| * smack_bprm_secureexec - Return the decision to use secureexec. |
| * @bprm: binprm for exec |
| * |
| * Returns 0 on success. |
| */ |
| static int smack_bprm_secureexec(struct linux_binprm *bprm) |
| { |
| struct task_smack *tsp = current_security(); |
| int ret = cap_bprm_secureexec(bprm); |
| |
| if (!ret && (tsp->smk_task != tsp->smk_forked)) |
| ret = 1; |
| |
| return ret; |
| } |
| |
| /* |
| * Inode hooks |
| */ |
| |
| /** |
| * smack_inode_alloc_security - allocate an inode blob |
| * @inode: the inode in need of a blob |
| * |
| * Returns 0 if it gets a blob, -ENOMEM otherwise |
| */ |
| static int smack_inode_alloc_security(struct inode *inode) |
| { |
| struct smack_known *skp = smk_of_current(); |
| |
| inode->i_security = new_inode_smack(skp); |
| if (inode->i_security == NULL) |
| return -ENOMEM; |
| return 0; |
| } |
| |
| /** |
| * smack_inode_free_security - free an inode blob |
| * @inode: the inode with a blob |
| * |
| * Clears the blob pointer in inode |
| */ |
| static void smack_inode_free_security(struct inode *inode) |
| { |
| kmem_cache_free(smack_inode_cache, inode->i_security); |
| inode->i_security = NULL; |
| } |
| |
| /** |
| * smack_inode_init_security - copy out the smack from an inode |
| * @inode: the newly created inode |
| * @dir: containing directory object |
| * @qstr: unused |
| * @name: where to put the attribute name |
| * @value: where to put the attribute value |
| * @len: where to put the length of the attribute |
| * |
| * 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, const char **name, |
| void **value, size_t *len) |
| { |
| struct inode_smack *issp = inode->i_security; |
| struct smack_known *skp = smk_of_current(); |
| struct smack_known *isp = smk_of_inode(inode); |
| struct smack_known *dsp = smk_of_inode(dir); |
| int may; |
| |
| if (name) |
| *name = XATTR_SMACK_SUFFIX; |
| |
| if (value && len) { |
| rcu_read_lock(); |
| may = smk_access_entry(skp->smk_known, dsp->smk_known, |
| &skp->smk_rules); |
| rcu_read_unlock(); |
| |
| /* |
| * If the access rule allows transmutation and |
| * the directory requests transmutation then |
| * by all means transmute. |
| * Mark the inode as changed. |
| */ |
| if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && |
| smk_inode_transmutable(dir)) { |
| isp = dsp; |
| issp->smk_flags |= SMK_INODE_CHANGED; |
| } |
| |
| *value = kstrdup(isp->smk_known, GFP_NOFS); |
| if (*value == NULL) |
| return -ENOMEM; |
| |
| *len = strlen(isp->smk_known); |
| } |
| |
| 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(old_dentry->d_inode); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(old_dentry->d_inode, MAY_WRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(new_dentry->d_inode); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(new_dentry->d_inode, 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 = dentry->d_inode; |
| 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(dentry->d_inode), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dentry->d_inode, 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(old_dentry->d_inode); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(old_dentry->d_inode, MAY_READWRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(new_dentry->d_inode); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(new_dentry->d_inode, 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, -EACCES otherwise |
| */ |
| static int smack_inode_permission(struct inode *inode, int mask) |
| { |
| 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; |
| |
| /* 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 |
| * @dentry: the object |
| * @iattr: for the force flag |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_setattr(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(dentry->d_inode), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_getattr - Smack check for getting attributes |
| * @mnt: vfsmount of the object |
| * @dentry: the object |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) |
| { |
| struct smk_audit_info ad; |
| struct path path; |
| int rc; |
| |
| path.dentry = dentry; |
| path.mnt = mnt; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, path); |
| rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); |
| rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_setxattr - Smack check for setting xattrs |
| * @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 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 (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 (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(dentry->d_inode), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dentry->d_inode, 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 = dentry->d_inode->i_security; |
| |
| 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 (skp != NULL) |
| isp->smk_inode = skp; |
| else |
| isp->smk_inode = &smack_known_invalid; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { |
| skp = smk_import_entry(value, size); |
| if (skp != NULL) |
| isp->smk_task = skp; |
| else |
| isp->smk_task = &smack_known_invalid; |
| } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| skp = smk_import_entry(value, size); |
| if (skp != NULL) |
| isp->smk_mmap = skp; |
| else |
| isp->smk_mmap = &smack_known_invalid; |
| } |
| |
| 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(dentry->d_inode), MAY_READ, &ad); |
| rc = smk_bu_inode(dentry->d_inode, MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_removexattr - Smack check on removexattr |
| * @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 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(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(dentry->d_inode), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dentry->d_inode, MAY_WRITE, rc); |
| if (rc != 0) |
| return rc; |
| |
| isp = dentry->d_inode->i_security; |
| /* |
| * Don't do anything special for these. |
| * XATTR_NAME_SMACKIPIN |
| * XATTR_NAME_SMACKIPOUT |
| * XATTR_NAME_SMACKEXEC |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 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_getsecurity - get smack xattrs |
| * @inode: the object |
| * @name: attribute name |
| * @buffer: where to put the result |
| * @alloc: unused |
| * |
| * Returns the size of the attribute or an error code |
| */ |
| static int smack_inode_getsecurity(const struct inode *inode, |
| const char *name, void **buffer, |
| bool alloc) |
| { |
| struct socket_smack *ssp; |
| struct socket *sock; |
| struct super_block *sbp; |
| struct inode *ip = (struct inode *)inode; |
| struct smack_known *isp; |
| int ilen; |
| int rc = 0; |
| |
| if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
| isp = smk_of_inode(inode); |
| ilen = strlen(isp->smk_known); |
| *buffer = isp->smk_known; |
| return ilen; |
| } |
| |
| /* |
| * 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; |
| |
| ilen = strlen(isp->smk_known); |
| if (rc == 0) { |
| *buffer = isp->smk_known; |
| rc = ilen; |
| } |
| |
| return rc; |
| } |
| |
| |
| /** |
| * smack_inode_listsecurity - list the Smack attributes |
| * @inode: the object |
| * @buffer: where they go |
| * @buffer_size: size of buffer |
| * |
| * Returns 0 on success, -EINVAL otherwise |
| */ |
| 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(const struct inode *inode, u32 *secid) |
| { |
| struct inode_smack *isp = inode->i_security; |
| |
| *secid = isp->smk_inode->smk_secid; |
| } |
| |
| /* |
| * File Hooks |
| */ |
| |
| /** |
| * smack_file_permission - Smack check on file operations |
| * @file: unused |
| * @mask: unused |
| * |
| * Returns 0 |
| * |
| * 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. |
| */ |
| static int smack_file_permission(struct file *file, int mask) |
| { |
| return 0; |
| } |
| |
| /** |
| * 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 *skp = smk_of_current(); |
| |
| file->f_security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_file_free_security - clear a file security blob |
| * @file: the object |
| * |
| * The security blob for a file is a pointer to the master |
| * label list, so no memory is freed. |
| */ |
| static void smack_file_free_security(struct file *file) |
| { |
| file->f_security = NULL; |
| } |
| |
| /** |
| * 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); |
| |
| 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); |
| |
| 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); |
| |
| 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. The @file may be NULL, e.g. |
| * if mapping anonymous memory. |
| * @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. |
| * 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; |
| int may; |
| int mmay; |
| int tmay; |
| int rc; |
| |
| if (file == NULL) |
| return 0; |
| |
| isp = file_inode(file)->i_security; |
| if (isp->smk_mmap == NULL) |
| return 0; |
| mkp = isp->smk_mmap; |
| |
| tsp = current_security(); |
| 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) |
| { |
| file->f_security = 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 *skp; |
| struct smack_known *tkp = smk_of_task(tsk->cred->security); |
| 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 */ |
| skp = file->f_security; |
| rc = smk_access(skp, tkp, MAY_WRITE, NULL); |
| rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc); |
| if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) |
| rc = 0; |
| |
| 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_WRITE, 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); |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| /* |
| * 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 |
| * @cred: task credential |
| * |
| * 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 |
| */ |
| static int smack_file_open(struct file *file, const struct cred *cred) |
| { |
| struct task_smack *tsp = cred->security; |
| struct inode *inode = file_inode(file); |
| struct smk_audit_info ad; |
| int rc; |
| |
| if (smack_privileged(CAP_MAC_OVERRIDE)) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_credfile(cred, file, MAY_READ, rc); |
| |
| return rc; |
| } |
| |
| /* |
| * Task hooks |
| */ |
| |
| /** |
| * smack_cred_alloc_blank - "allocate" blank task-level security credentials |
| * @new: 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) |
| { |
| struct task_smack *tsp; |
| |
| tsp = new_task_smack(NULL, NULL, gfp); |
| if (tsp == NULL) |
| return -ENOMEM; |
| |
| cred->security = tsp; |
| |
| 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 = cred->security; |
| struct smack_rule *rp; |
| struct list_head *l; |
| struct list_head *n; |
| |
| if (tsp == NULL) |
| return; |
| cred->security = NULL; |
| |
| list_for_each_safe(l, n, &tsp->smk_rules) { |
| rp = list_entry(l, struct smack_rule, list); |
| list_del(&rp->list); |
| kfree(rp); |
| } |
| kfree(tsp); |
| } |
| |
| /** |
| * 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 = old->security; |
| struct task_smack *new_tsp; |
| int rc; |
| |
| new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); |
| if (new_tsp == NULL) |
| return -ENOMEM; |
| |
| rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); |
| if (rc != 0) |
| return rc; |
| |
| new->security = new_tsp; |
| return 0; |
| } |
| |
| /** |
| * 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 = old->security; |
| struct task_smack *new_tsp = new->security; |
| |
| new_tsp->smk_task = old_tsp->smk_task; |
| new_tsp->smk_forked = old_tsp->smk_task; |
| mutex_init(&new_tsp->smk_rules_lock); |
| INIT_LIST_HEAD(&new_tsp->smk_rules); |
| |
| |
| /* cbs copy rule list */ |
| } |
| |
| /** |
| * 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 = new->security; |
| struct smack_known *skp = smack_from_secid(secid); |
| |
| if (skp == NULL) |
| return -EINVAL; |
| |
| new_tsp->smk_task = skp; |
| 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 = inode->i_security; |
| struct task_smack *tsp = new->security; |
| |
| 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(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_task_getsecid - get the secid of the task |
| * @p: the object task |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the smack label. |
| */ |
| static void smack_task_getsecid(struct task_struct *p, u32 *secid) |
| { |
| struct smack_known *skp = smk_of_task_struct(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) |
| { |
| int rc; |
| |
| rc = cap_task_setnice(p, nice); |
| if (rc == 0) |
| rc = smk_curacc_on_task(p, MAY_WRITE, __func__); |
| return rc; |
| } |
| |
| /** |
| * 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) |
| { |
| int rc; |
| |
| rc = cap_task_setioprio(p, ioprio); |
| if (rc == 0) |
| rc = smk_curacc_on_task(p, MAY_WRITE, __func__); |
| return rc; |
| } |
| |
| /** |
| * 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 |
| * @policy: unused |
| * @lp: unused |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_setscheduler(struct task_struct *p) |
| { |
| int rc; |
| |
| rc = cap_task_setscheduler(p); |
| if (rc == 0) |
| rc = smk_curacc_on_task(p, MAY_WRITE, __func__); |
| return rc; |
| } |
| |
| /** |
| * 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 |
| * @secid: identifies the smack to use in lieu of current's |
| * |
| * Return 0 if write access is permitted |
| * |
| * The secid behavior is an artifact of an SELinux hack |
| * in the USB code. Someday it may go away. |
| */ |
| static int smack_task_kill(struct task_struct *p, struct siginfo *info, |
| int sig, u32 secid) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp; |
| struct smack_known *tkp = smk_of_task_struct(p); |
| int rc; |
| |
| 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 (secid == 0) { |
| rc = smk_curacc(tkp, MAY_WRITE, &ad); |
| rc = smk_bu_task(p, MAY_WRITE, rc); |
| return rc; |
| } |
| /* |
| * If the secid isn't 0 we're dealing with some USB IO |
| * specific behavior. This is not clean. For one thing |
| * we can't take privilege into account. |
| */ |
| skp = smack_from_secid(secid); |
| rc = smk_access(skp, tkp, MAY_WRITE, &ad); |
| rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_task_wait - Smack access check for waiting |
| * @p: task to wait for |
| * |
| * Returns 0 |
| */ |
| static int smack_task_wait(struct task_struct *p) |
| { |
| /* |
| * Allow the operation to succeed. |
| * Zombies are bad. |
| * In userless environments (e.g. phones) programs |
| * get marked with SMACK64EXEC and even if the parent |
| * and child shouldn't be talking the parent still |
| * may expect to know when the child exits. |
| */ |
| return 0; |
| } |
| |
| /** |
| * 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 = inode->i_security; |
| struct smack_known *skp = smk_of_task_struct(p); |
| |
| isp->smk_inode = skp; |
| } |
| |
| /* |
| * 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; |
| |
| 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) |
| { |
| kfree(sk->sk_security); |
| } |
| |
| /** |
| * smack_host_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_host_label(struct sockaddr_in *sip) |
| { |
| struct smk_netlbladdr *snp; |
| struct in_addr *siap = &sip->sin_addr; |
| |
| if (siap->s_addr == 0) |
| return NULL; |
| |
| list_for_each_entry_rcu(snp, &smk_netlbladdr_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.sin_addr)->s_addr == |
| (siap->s_addr & (&snp->smk_mask)->s_addr)) { |
| /* we have found the special CIPSO option */ |
| if (snp->smk_label == &smack_cipso_option) |
| return NULL; |
| return snp->smk_label; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * smack_netlabel - Set the secattr on a socket |
| * @sk: the socket |
| * @labeled: socket label scheme |
| * |
| * Convert the outbound smack value (smk_out) to a |
| * secattr and attach it to the socket. |
| * |
| * Returns 0 on success or an error code |
| */ |
| static int smack_netlabel(struct sock *sk, int labeled) |
| { |
| struct smack_known *skp; |
| struct socket_smack *ssp = sk->sk_security; |
| int rc = 0; |
| |
| /* |
| * Usually the netlabel code will handle changing the |
| * packet labeling based on the label. |
| * The case of a single label host is different, because |
| * a single label host should never get a labeled packet |
| * even though the label is usually associated with a packet |
| * label. |
| */ |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| |
| if (ssp->smk_out == smack_net_ambient || |
| labeled == SMACK_UNLABELED_SOCKET) |
| netlbl_sock_delattr(sk); |
| else { |
| skp = ssp->smk_out; |
| rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); |
| } |
| |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_netlbel_send - Set the secattr on a socket and perform 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 smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) |
| { |
| struct smack_known *skp; |
| int rc; |
| int sk_lbl; |
| struct smack_known *hkp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smk_audit_info ad; |
| |
| rcu_read_lock(); |
| hkp = smack_host_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 |
| sk_lbl = SMACK_UNLABELED_SOCKET; |
| skp = ssp->smk_out; |
| rc = smk_access(skp, hkp, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); |
| } else { |
| sk_lbl = SMACK_CIPSO_SOCKET; |
| rc = 0; |
| } |
| rcu_read_unlock(); |
| if (rc != 0) |
| return rc; |
| |
| return smack_netlabel(sk, sk_lbl); |
| } |
| |
| #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) |
| /** |
| * 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. |
| */ |
| list_for_each_entry(spp, &smk_ipv6_port_list, list) { |
| if (sk != spp->smk_sock) |
| continue; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| return; |
| } |
| /* |
| * A NULL address is only used for updating existing |
| * bound entries. If there isn't one, it's OK. |
| */ |
| 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. |
| */ |
| list_for_each_entry(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port) |
| continue; |
| spp->smk_port = port; |
| spp->smk_sock = sk; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| return; |
| } |
| |
| /* |
| * 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; |
| |
| list_add(&spp->list, &smk_ipv6_port_list); |
| return; |
| } |
| |
| /** |
| * smk_ipv6_port_check - check Smack port access |
| * @sock: socket |
| * @address: address |
| * |
| * Create or update the port list entry |
| */ |
| static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, |
| int act) |
| { |
| __be16 *bep; |
| __be32 *be32p; |
| struct smk_port_label *spp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp; |
| unsigned short port = 0; |
| struct smack_known *object; |
| struct smk_audit_info ad; |
| int rc; |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| |
| if (act == SMK_RECEIVING) { |
| skp = smack_net_ambient; |
| object = ssp->smk_in; |
| } else { |
| skp = ssp->smk_out; |
| object = smack_net_ambient; |
| } |
| |
| /* |
| * Get the IP address and port from the address. |
| */ |
| port = ntohs(address->sin6_port); |
| bep = (__be16 *)(&address->sin6_addr); |
| be32p = (__be32 *)(&address->sin6_addr); |
| |
| /* |
| * It's remote, so port lookup does no good. |
| */ |
| if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1) |
| goto auditout; |
| |
| /* |
| * It's local so the send check has to have passed. |
| */ |
| if (act == SMK_RECEIVING) { |
| skp = &smack_known_web; |
| goto auditout; |
| } |
| |
| list_for_each_entry(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port) |
| continue; |
| object = spp->smk_in; |
| if (act == SMK_CONNECTING) |
| ssp->smk_packet = spp->smk_out; |
| break; |
| } |
| |
| auditout: |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = sk->sk_family; |
| ad.a.u.net->dport = 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(skp, object, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc); |
| return rc; |
| } |
| #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */ |
| |
| /** |
| * 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 = inode->i_security; |
| struct socket_smack *ssp; |
| struct socket *sock; |
| int rc = 0; |
| |
| if (value == NULL || size > SMK_LONGLABEL || size == 0) |
| return -EINVAL; |
| |
| skp = smk_import_entry(value, size); |
| if (skp == NULL) |
| return -EINVAL; |
| |
| 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_netlabel(sock->sk, SMACK_CIPSO_SOCKET); |
| if (rc != 0) |
| printk(KERN_WARNING |
| "Smack: \"%s\" netlbl error %d.\n", |
| __func__, -rc); |
| } |
| } else |
| return -EOPNOTSUPP; |
| |
| #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) |
| if (sock->sk->sk_family == PF_INET6) |
| smk_ipv6_port_label(sock, NULL); |
| #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */ |
| |
| 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) |
| { |
| if (family != PF_INET || sock->sk == NULL) |
| return 0; |
| /* |
| * Set the outbound netlbl. |
| */ |
| return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); |
| } |
| |
| #ifndef CONFIG_SECURITY_SMACK_NETFILTER |
| /** |
| * 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 |
| */ |
| static int smack_socket_bind(struct socket *sock, struct sockaddr *address, |
| int addrlen) |
| { |
| #if IS_ENABLED(CONFIG_IPV6) |
| if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) |
| smk_ipv6_port_label(sock, address); |
| #endif |
| |
| return 0; |
| } |
| #endif /* !CONFIG_SECURITY_SMACK_NETFILTER */ |
| |
| /** |
| * 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; |
| |
| switch (sock->sk->sk_family) { |
| case PF_INET: |
| if (addrlen < sizeof(struct sockaddr_in)) |
| return -EINVAL; |
| rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); |
| break; |
| case PF_INET6: |
| if (addrlen < sizeof(struct sockaddr_in6)) |
| return -EINVAL; |
| #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER) |
| rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap, |
| SMK_CONNECTING); |
| #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */ |
| break; |
| } |
| 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 *skp = smk_of_current(); |
| |
| msg->security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_msg_msg_free_security - Clear the security blob for msg_msg |
| * @msg: the object |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_msg_msg_free_security(struct msg_msg *msg) |
| { |
| msg->security = NULL; |
| } |
| |
| /** |
| * smack_of_shm - the smack pointer for the shm |
| * @shp: the object |
| * |
| * Returns a pointer to the smack value |
| */ |
| static struct smack_known *smack_of_shm(struct shmid_kernel *shp) |
| { |
| return (struct smack_known *)shp->shm_perm.security; |
| } |
| |
| /** |
| * smack_shm_alloc_security - Set the security blob for shm |
| * @shp: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_shm_alloc_security(struct shmid_kernel *shp) |
| { |
| struct kern_ipc_perm *isp = &shp->shm_perm; |
| struct smack_known *skp = smk_of_current(); |
| |
| isp->security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_shm_free_security - Clear the security blob for shm |
| * @shp: the object |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_shm_free_security(struct shmid_kernel *shp) |
| { |
| struct kern_ipc_perm *isp = &shp->shm_perm; |
| |
| isp->security = NULL; |
| } |
| |
| /** |
| * smk_curacc_shm : check if current has access on shm |
| * @shp : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_shm(struct shmid_kernel *shp, int access) |
| { |
| struct smack_known *ssp = smack_of_shm(shp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = shp->shm_perm.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 |
| * @shp: the object |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(shp, may); |
| } |
| |
| /** |
| * smack_shm_shmctl - Smack access check for shm |
| * @shp: 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 shmid_kernel *shp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case IPC_STAT: |
| case SHM_STAT: |
| 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(shp, may); |
| } |
| |
| /** |
| * smack_shm_shmat - Smack access for shmat |
| * @shp: the object |
| * @shmaddr: unused |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, |
| int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(shp, may); |
| } |
| |
| /** |
| * smack_of_sem - the smack pointer for the sem |
| * @sma: the object |
| * |
| * Returns a pointer to the smack value |
| */ |
| static struct smack_known *smack_of_sem(struct sem_array *sma) |
| { |
| return (struct smack_known *)sma->sem_perm.security; |
| } |
| |
| /** |
| * smack_sem_alloc_security - Set the security blob for sem |
| * @sma: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_sem_alloc_security(struct sem_array *sma) |
| { |
| struct kern_ipc_perm *isp = &sma->sem_perm; |
| struct smack_known *skp = smk_of_current(); |
| |
| isp->security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_sem_free_security - Clear the security blob for sem |
| * @sma: the object |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_sem_free_security(struct sem_array *sma) |
| { |
| struct kern_ipc_perm *isp = &sma->sem_perm; |
| |
| isp->security = NULL; |
| } |
| |
| /** |
| * smk_curacc_sem : check if current has access on sem |
| * @sma : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_sem(struct sem_array *sma, int access) |
| { |
| struct smack_known *ssp = smack_of_sem(sma); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = sma->sem_perm.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 |
| * @sma: the object |
| * @semflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_sem_associate(struct sem_array *sma, int semflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(semflg); |
| return smk_curacc_sem(sma, may); |
| } |
| |
| /** |
| * smack_sem_shmctl - Smack access check for sem |
| * @sma: 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 sem_array *sma, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case GETPID: |
| case GETNCNT: |
| case GETZCNT: |
| case GETVAL: |
| case GETALL: |
| case IPC_STAT: |
| case SEM_STAT: |
| 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; |
| } |
| |
| return smk_curacc_sem(sma, may); |
| } |
| |
| /** |
| * smack_sem_semop - Smack checks of semaphore operations |
| * @sma: the object |
| * @sops: unused |
| * @nsops: unused |
| * @alter: unused |
| * |
| * Treated as read and write in all cases. |
| * |
| * Returns 0 if access is allowed, error code otherwise |
| */ |
| static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, |
| unsigned nsops, int alter) |
| { |
| return smk_curacc_sem(sma, MAY_READWRITE); |
| } |
| |
| /** |
| * smack_msg_alloc_security - Set the security blob for msg |
| * @msq: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_msg_queue_alloc_security(struct msg_queue *msq) |
| { |
| struct kern_ipc_perm *kisp = &msq->q_perm; |
| struct smack_known *skp = smk_of_current(); |
| |
| kisp->security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_msg_free_security - Clear the security blob for msg |
| * @msq: the object |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_msg_queue_free_security(struct msg_queue *msq) |
| { |
| struct kern_ipc_perm *kisp = &msq->q_perm; |
| |
| kisp->security = NULL; |
| } |
| |
| /** |
| * smack_of_msq - the smack pointer for the msq |
| * @msq: the object |
| * |
| * Returns a pointer to the smack label entry |
| */ |
| static struct smack_known *smack_of_msq(struct msg_queue *msq) |
| { |
| return (struct smack_known *)msq->q_perm.security; |
| } |
| |
| /** |
| * smk_curacc_msq : helper to check if current has access on msq |
| * @msq : the msq |
| * @access : access requested |
| * |
| * return 0 if current has access, error otherwise |
| */ |
| static int smk_curacc_msq(struct msg_queue *msq, int access) |
| { |
| struct smack_known *msp = smack_of_msq(msq); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = msq->q_perm.id; |
| #endif |
| rc = smk_curacc(msp, access, &ad); |
| rc = smk_bu_current("msq", msp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_msg_queue_associate - Smack access check for msg_queue |
| * @msq: the object |
| * @msqflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(msqflg); |
| return smk_curacc_msq(msq, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgctl - Smack access check for msg_queue |
| * @msq: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case IPC_STAT: |
| case MSG_STAT: |
| may = MAY_READ; |
| break; |
| case IPC_SET: |
| case IPC_RMID: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case MSG_INFO: |
| /* |
| * System level information |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| |
| return smk_curacc_msq(msq, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgsnd - Smack access check for msg_queue |
| * @msq: the object |
| * @msg: unused |
| * @msqflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, |
| int msqflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(msqflg); |
| return smk_curacc_msq(msq, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgsnd - Smack access check for msg_queue |
| * @msq: the object |
| * @msg: unused |
| * @target: unused |
| * @type: unused |
| * @mode: unused |
| * |
| * Returns 0 if current has read and write access, error code otherwise |
| */ |
| static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, |
| struct task_struct *target, long type, int mode) |
| { |
| return smk_curacc_msq(msq, MAY_READWRITE); |
| } |
| |
| /** |
| * smack_ipc_permission - Smack access for ipc_permission() |
| * @ipp: the object permissions |
| * @flag: access requested |
| * |
| * Returns 0 if current has read and write access, error code otherwise |
| */ |
| static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) |
| { |
| struct smack_known *iskp = ipp->security; |
| int may = smack_flags_to_may(flag); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = ipp->id; |
| #endif |
| rc = smk_curacc(iskp, may, &ad); |
| rc = smk_bu_current("svipc", iskp, may, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_ipc_getsecid - Extract smack security id |
| * @ipp: the object permissions |
| * @secid: where result will be saved |
| */ |
| static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) |
| { |
| struct smack_known *iskp = ipp->security; |
| |
| *secid = iskp->smk_secid; |
| } |
| |
| /** |
| * smack_d_instantiate - Make sure the blob is correct on an inode |
| * @opt_dentry: dentry where inode will be attached |
| * @inode: the object |
| * |
| * Set the inode's security blob if it hasn't been done already. |
| */ |
| static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) |
| { |
| struct super_block *sbp; |
| struct superblock_smack *sbsp; |
| struct inode_smack *isp; |
| struct smack_known *skp; |
| struct smack_known *ckp = smk_of_current(); |
| struct smack_known *final; |
| char trattr[TRANS_TRUE_SIZE]; |
| int transflag = 0; |
| int rc; |
| struct dentry *dp; |
| |
| if (inode == NULL) |
| return; |
| |
| isp = inode->i_security; |
| |
| mutex_lock(&isp->smk_lock); |
| /* |
| * If the inode is already instantiated |
| * take the quick way out |
| */ |
| if (isp->smk_flags & SMK_INODE_INSTANT) |
| goto unlockandout; |
| |
| sbp = inode->i_sb; |
| sbsp = sbp->s_security; |
| /* |
| * We're going to use the superblock default label |
| * if there's no label on the file. |
| */ |
| final = sbsp->smk_default; |
| |
| /* |
| * If this is the root inode the superblock |
| * may be in the process of initialization. |
| * If that is the case use the root value out |
| * of the superblock. |
| */ |
| if (opt_dentry->d_parent == opt_dentry) { |
| switch (sbp->s_magic) { |
| case CGROUP_SUPER_MAGIC: |
| /* |
| * The cgroup filesystem is never mounted, |
| * so there's no opportunity to set the mount |
| * options. |
| */ |
| sbsp->smk_root = &smack_known_star; |
| sbsp->smk_default = &smack_known_star; |
| isp->smk_inode = sbsp->smk_root; |
| break; |
| case TMPFS_MAGIC: |
| /* |
| * What about shmem/tmpfs anonymous files with dentry |
| * obtained from d_alloc_pseudo()? |
| */ |
| isp->smk_inode = smk_of_current(); |
| break; |
| default: |
| isp->smk_inode = sbsp->smk_root; |
| break; |
| } |
| isp->smk_flags |= SMK_INODE_INSTANT; |
| goto unlockandout; |
| } |
| |
| /* |
| * This is pretty hackish. |
| * Casey says that we shouldn't have to do |
| * file system specific code, but it does help |
| * with keeping it simple. |
| */ |
| switch (sbp->s_magic) { |
| case SMACK_MAGIC: |
| case PIPEFS_MAGIC: |
| case SOCKFS_MAGIC: |
| case CGROUP_SUPER_MAGIC: |
| /* |
| * Casey says that it's a little embarrassing |
| * that the smack file system doesn't do |
| * extended attributes. |
| * |
| * Casey says pipes are easy (?) |
| * |
| * Socket access is controlled by the socket |
| * structures associated with the task involved. |
| * |
| * Cgroupfs is special |
| */ |
| final = &smack_known_star; |
| break; |
| case DEVPTS_SUPER_MAGIC: |
| /* |
| * devpts seems content with the label of the task. |
| * Programs that change smack have to treat the |
| * pty with respect. |
| */ |
| final = ckp; |
| break; |
| case PROC_SUPER_MAGIC: |
| /* |
| * Casey says procfs appears not to care. |
| * The superblock default suffices. |
| */ |
| break; |
| case TMPFS_MAGIC: |
| /* |
| * Device labels should come from the filesystem, |
| * but watch out, because they're volitile, |
| * getting recreated on every reboot. |
| */ |
| final = &smack_known_star; |
| /* |
| * No break. |
| * |
| * If a smack value has been set we want to use it, |
| * but since tmpfs isn't giving us the opportunity |
| * to set mount options simulate setting the |
| * superblock default. |
| */ |
| default: |
| /* |
| * This isn't an understood special case. |
| * Get the value from the xattr. |
| */ |
| |
| /* |
| * UNIX domain sockets use lower level socket data. |
| */ |
| if (S_ISSOCK(inode->i_mode)) { |
| final = &smack_known_star; |
| break; |
| } |
| /* |
| * No xattr support means, alas, no SMACK label. |
| * Use the aforeapplied default. |
| * It would be curious if the label of the task |
| * does not match that assigned. |
| */ |
| if (inode->i_op->getxattr == NULL) |
| break; |
| /* |
| * Get the dentry for xattr. |
| */ |
| dp = dget(opt_dentry); |
| skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); |
| if (skp != NULL) |
| final = skp; |
| |
| /* |
| * Transmuting directory |
| */ |
| if (S_ISDIR(inode->i_mode)) { |
| /* |
| * If this is a new directory and the label was |
| * transmuted when the inode was initialized |
| * set the transmute attribute on the directory |
| * and mark the inode. |
| * |
| * If there is a transmute attribute on the |
| * directory mark the inode. |
| */ |
| if (isp->smk_flags & SMK_INODE_CHANGED) { |
| isp->smk_flags &= ~SMK_INODE_CHANGED; |
| rc = inode->i_op->setxattr(dp, |
| XATTR_NAME_SMACKTRANSMUTE, |
| TRANS_TRUE, TRANS_TRUE_SIZE, |
| 0); |
| } else { |
| rc = inode->i_op->getxattr(dp, |
| XATTR_NAME_SMACKTRANSMUTE, trattr, |
| TRANS_TRUE_SIZE); |
| if (rc >= 0 && strncmp(trattr, TRANS_TRUE, |
| TRANS_TRUE_SIZE) != 0) |
| rc = -EINVAL; |
| } |
| if (rc >= 0) |
| transflag = SMK_INODE_TRANSMUTE; |
| } |
| /* |
| * Don't let the exec or mmap label be "*" or "@". |
| */ |
| skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); |
| if (skp == &smack_known_star || skp == &smack_known_web) |
| skp = NULL; |
| isp->smk_task = skp; |
| skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); |
| if (skp == &smack_known_star || skp == &smack_known_web) |
| skp = NULL; |
| isp->smk_mmap = skp; |
| |
| dput(dp); |
| break; |
| } |
| |
| if (final == NULL) |
| isp->smk_inode = ckp; |
| else |
| isp->smk_inode = final; |
| |
| isp->smk_flags |= (SMK_INODE_INSTANT | transflag); |
| |
| unlockandout: |
| mutex_unlock(&isp->smk_lock); |
| return; |
| } |
| |
| /** |
| * smack_getprocattr - Smack process attribute access |
| * @p: the object task |
| * @name: the name of the attribute in /proc/.../attr |
| * @value: where to put the result |
| * |
| * Places a copy of the task Smack into value |
| * |
| * Returns the length of the smack label or an error code |
| */ |
| static int smack_getprocattr(struct task_struct *p, char *name, char **value) |
| { |
| struct smack_known *skp = smk_of_task_struct(p); |
| char *cp; |
| int slen; |
| |
| if (strcmp(name, "current") != 0) |
| return -EINVAL; |
| |
| cp = kstrdup(skp->smk_known, GFP_KERNEL); |
| if (cp == NULL) |
| return -ENOMEM; |
| |
| slen = strlen(cp); |
| *value = cp; |
| return slen; |
| } |
| |
| /** |
| * smack_setprocattr - Smack process attribute setting |
| * @p: the object task |
| * @name: the name of the attribute in /proc/.../attr |
| * @value: the value to set |
| * @size: the size of the value |
| * |
| * Sets the Smack value of the task. Only setting self |
| * is permitted and only with privilege |
| * |
| * Returns the length of the smack label or an error code |
| */ |
| static int smack_setprocattr(struct task_struct *p, char *name, |
| void *value, size_t size) |
| { |
| struct task_smack *tsp; |
| struct cred *new; |
| struct smack_known *skp; |
| |
| /* |
| * Changing another process' Smack value is too dangerous |
| * and supports no sane use case. |
| */ |
| if (p != current) |
| return -EPERM; |
| |
| if (!smack_privileged(CAP_MAC_ADMIN)) |
| return -EPERM; |
| |
| if (value == NULL || size == 0 || size >= SMK_LONGLABEL) |
| return -EINVAL; |
| |
| if (strcmp(name, "current") != 0) |
| return -EINVAL; |
| |
| skp = smk_import_entry(value, size); |
| if (skp == NULL) |
| return -EINVAL; |
| |
| /* |
| * No process is ever allowed the web ("@") label. |
| */ |
| if (skp == &smack_known_web) |
| return -EPERM; |
| |
| new = prepare_creds(); |
| if (new == NULL) |
| return -ENOMEM; |
| |
| tsp = new->security; |
| tsp->smk_task = skp; |
| |
| commit_creds(new); |
| return size; |
| } |
| |
| /** |
| * smack_unix_stream_connect - Smack access on UDS |
| * @sock: one sock |
| * @other: the other sock |
| * @newsk: unused |
| * |
| * Return 0 if a subject with the smack of sock could access |
| * an object with the smack of other, otherwise an error code |
| */ |
| static int smack_unix_stream_connect(struct sock *sock, |
| struct sock *other, struct sock *newsk) |
| { |
| struct smack_known *skp; |
| struct smack_known *okp; |
| struct socket_smack *ssp = sock->sk_security; |
| struct socket_smack *osp = other->sk_security; |
| struct socket_smack *nsp = newsk->sk_security; |
| struct smk_audit_info ad; |
| int rc = 0; |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| |
| if (!smack_privileged(CAP_MAC_OVERRIDE)) { |
| skp = ssp->smk_out; |
| okp = osp->smk_in; |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| smk_ad_setfield_u_net_sk(&ad, other); |
| #endif |
| rc = smk_access(skp, okp, MAY_WRITE, &ad); |
| rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); |
| if (rc == 0) { |
| okp = osp->smk_out; |
| skp = ssp->smk_in; |
| rc = smk_access(okp, skp, MAY_WRITE, &ad); |
| rc = smk_bu_note("UDS connect", okp, skp, |
| MAY_WRITE, rc); |
| } |
| } |
| |
| /* |
| * Cross reference the peer labels for SO_PEERSEC. |
| */ |
| if (rc == 0) { |
| nsp->smk_packet = ssp->smk_out; |
| ssp->smk_packet = osp->smk_out; |
| } |
| |
| return rc; |
| } |
| |
| |