]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
CRED: Wrap access to SELinux's task SID
authorDavid Howells <dhowells@redhat.com>
Thu, 13 Nov 2008 23:39:19 +0000 (10:39 +1100)
committerJames Morris <jmorris@namei.org>
Thu, 13 Nov 2008 23:39:19 +0000 (10:39 +1100)
Wrap access to SELinux's task SID, using task_sid() and current_sid() as
appropriate.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
security/selinux/hooks.c

index 658435dce37cd05a0280a15b1696443f3cb4dc6b..3f3de565c24261e61f17dff2c72cc76a889f0407 100644 (file)
@@ -172,10 +172,35 @@ static int cred_alloc_security(struct cred *cred)
        return 0;
 }
 
+/*
+ * get the security ID of a task
+ */
+static inline u32 task_sid(const struct task_struct *task)
+{
+       const struct task_security_struct *tsec;
+       u32 sid;
+
+       rcu_read_lock();
+       tsec = __task_cred(task)->security;
+       sid = tsec->sid;
+       rcu_read_unlock();
+       return sid;
+}
+
+/*
+ * get the security ID of the current task
+ */
+static inline u32 current_sid(void)
+{
+       const struct task_security_struct *tsec = current_cred()->security;
+
+       return tsec->sid;
+}
+
 static int inode_alloc_security(struct inode *inode)
 {
-       struct task_security_struct *tsec = current->cred->security;
        struct inode_security_struct *isec;
+       u32 sid = current_sid();
 
        isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
        if (!isec)
@@ -186,7 +211,7 @@ static int inode_alloc_security(struct inode *inode)
        isec->inode = inode;
        isec->sid = SECINITSID_UNLABELED;
        isec->sclass = SECCLASS_FILE;
-       isec->task_sid = tsec->sid;
+       isec->task_sid = sid;
        inode->i_security = isec;
 
        return 0;
@@ -208,15 +233,15 @@ static void inode_free_security(struct inode *inode)
 
 static int file_alloc_security(struct file *file)
 {
-       struct task_security_struct *tsec = current->cred->security;
        struct file_security_struct *fsec;
+       u32 sid = current_sid();
 
        fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
        if (!fsec)
                return -ENOMEM;
 
-       fsec->sid = tsec->sid;
-       fsec->fown_sid = tsec->sid;
+       fsec->sid = sid;
+       fsec->fown_sid = sid;
        file->f_security = fsec;
 
        return 0;
@@ -331,8 +356,9 @@ static const match_table_t tokens = {
 
 static int may_context_mount_sb_relabel(u32 sid,
                        struct superblock_security_struct *sbsec,
-                       struct task_security_struct *tsec)
+                       const struct cred *cred)
 {
+       const struct task_security_struct *tsec = cred->security;
        int rc;
 
        rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
@@ -347,8 +373,9 @@ static int may_context_mount_sb_relabel(u32 sid,
 
 static int may_context_mount_inode_relabel(u32 sid,
                        struct superblock_security_struct *sbsec,
-                       struct task_security_struct *tsec)
+                       const struct cred *cred)
 {
+       const struct task_security_struct *tsec = cred->security;
        int rc;
        rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
                          FILESYSTEM__RELABELFROM, NULL);
@@ -546,8 +573,8 @@ static int bad_option(struct superblock_security_struct *sbsec, char flag,
 static int selinux_set_mnt_opts(struct super_block *sb,
                                struct security_mnt_opts *opts)
 {
+       const struct cred *cred = current_cred();
        int rc = 0, i;
-       struct task_security_struct *tsec = current->cred->security;
        struct superblock_security_struct *sbsec = sb->s_security;
        const char *name = sb->s_type->name;
        struct inode *inode = sbsec->sb->s_root->d_inode;
@@ -673,8 +700,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 
        /* sets the context of the superblock for the fs being mounted. */
        if (fscontext_sid) {
-
-               rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, tsec);
+               rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
                if (rc)
                        goto out;
 
@@ -688,12 +714,14 @@ static int selinux_set_mnt_opts(struct super_block *sb,
         */
        if (context_sid) {
                if (!fscontext_sid) {
-                       rc = may_context_mount_sb_relabel(context_sid, sbsec, tsec);
+                       rc = may_context_mount_sb_relabel(context_sid, sbsec,
+                                                         cred);
                        if (rc)
                                goto out;
                        sbsec->sid = context_sid;
                } else {
-                       rc = may_context_mount_inode_relabel(context_sid, sbsec, tsec);
+                       rc = may_context_mount_inode_relabel(context_sid, sbsec,
+                                                            cred);
                        if (rc)
                                goto out;
                }
@@ -705,7 +733,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
        }
 
        if (rootcontext_sid) {
-               rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, tsec);
+               rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
+                                                    cred);
                if (rc)
                        goto out;
 
@@ -723,7 +752,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 
                if (defcontext_sid != sbsec->def_sid) {
                        rc = may_context_mount_inode_relabel(defcontext_sid,
-                                                            sbsec, tsec);
+                                                            sbsec, cred);
                        if (rc)
                                goto out;
                }
@@ -1338,18 +1367,23 @@ static inline u32 signal_to_av(int sig)
        return perm;
 }
 
-/* Check permission betweeen a pair of tasks, e.g. signal checks,
-   fork check, ptrace check, etc. */
-static int task_has_perm(struct task_struct *tsk1,
-                        struct task_struct *tsk2,
+/*
+ * Check permission betweeen a pair of tasks, e.g. signal checks,
+ * fork check, ptrace check, etc.
+ * tsk1 is the actor and tsk2 is the target
+ */
+static int task_has_perm(const struct task_struct *tsk1,
+                        const struct task_struct *tsk2,
                         u32 perms)
 {
-       struct task_security_struct *tsec1, *tsec2;
+       const struct task_security_struct *__tsec1, *__tsec2;
+       u32 sid1, sid2;
 
-       tsec1 = tsk1->cred->security;
-       tsec2 = tsk2->cred->security;
-       return avc_has_perm(tsec1->sid, tsec2->sid,
-                           SECCLASS_PROCESS, perms, NULL);
+       rcu_read_lock();
+       __tsec1 = __task_cred(tsk1)->security;  sid1 = __tsec1->sid;
+       __tsec2 = __task_cred(tsk2)->security;  sid2 = __tsec2->sid;
+       rcu_read_unlock();
+       return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
 }
 
 #if CAP_LAST_CAP > 63
@@ -1360,15 +1394,13 @@ static int task_has_perm(struct task_struct *tsk1,
 static int task_has_capability(struct task_struct *tsk,
                               int cap, int audit)
 {
-       struct task_security_struct *tsec;
        struct avc_audit_data ad;
        struct av_decision avd;
        u16 sclass;
+       u32 sid = task_sid(tsk);
        u32 av = CAP_TO_MASK(cap);
        int rc;
 
-       tsec = tsk->cred->security;
-
        AVC_AUDIT_DATA_INIT(&ad, CAP);
        ad.tsk = tsk;
        ad.u.cap = cap;
@@ -1386,9 +1418,9 @@ static int task_has_capability(struct task_struct *tsk,
                BUG();
        }
 
-       rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, sclass, av, 0, &avd);
+       rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
        if (audit == SECURITY_CAP_AUDIT)
-               avc_audit(tsec->sid, tsec->sid, sclass, av, &avd, rc, &ad);
+               avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
        return rc;
 }
 
@@ -1396,11 +1428,9 @@ static int task_has_capability(struct task_struct *tsk,
 static int task_has_system(struct task_struct *tsk,
                           u32 perms)
 {
-       struct task_security_struct *tsec;
-
-       tsec = tsk->cred->security;
+       u32 sid = task_sid(tsk);
 
-       return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
+       return avc_has_perm(sid, SECINITSID_KERNEL,
                            SECCLASS_SYSTEM, perms, NULL);
 }
 
@@ -1412,14 +1442,14 @@ static int inode_has_perm(struct task_struct *tsk,
                          u32 perms,
                          struct avc_audit_data *adp)
 {
-       struct task_security_struct *tsec;
        struct inode_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid;
 
        if (unlikely(IS_PRIVATE(inode)))
                return 0;
 
-       tsec = tsk->cred->security;
+       sid = task_sid(tsk);
        isec = inode->i_security;
 
        if (!adp) {
@@ -1428,7 +1458,7 @@ static int inode_has_perm(struct task_struct *tsk,
                ad.u.fs.inode = inode;
        }
 
-       return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
+       return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
 }
 
 /* Same as inode_has_perm, but pass explicit audit data containing
@@ -1459,17 +1489,17 @@ static int file_has_perm(struct task_struct *tsk,
                                struct file *file,
                                u32 av)
 {
-       struct task_security_struct *tsec = tsk->cred->security;
        struct file_security_struct *fsec = file->f_security;
        struct inode *inode = file->f_path.dentry->d_inode;
        struct avc_audit_data ad;
+       u32 sid = task_sid(tsk);
        int rc;
 
        AVC_AUDIT_DATA_INIT(&ad, FS);
        ad.u.fs.path = file->f_path;
 
-       if (tsec->sid != fsec->sid) {
-               rc = avc_has_perm(tsec->sid, fsec->sid,
+       if (sid != fsec->sid) {
+               rc = avc_has_perm(sid, fsec->sid,
                                  SECCLASS_FD,
                                  FD__USE,
                                  &ad);
@@ -1489,36 +1519,36 @@ static int may_create(struct inode *dir,
                      struct dentry *dentry,
                      u16 tclass)
 {
-       struct task_security_struct *tsec;
+       const struct cred *cred = current_cred();
+       const struct task_security_struct *tsec = cred->security;
        struct inode_security_struct *dsec;
        struct superblock_security_struct *sbsec;
-       u32 newsid;
+       u32 sid, newsid;
        struct avc_audit_data ad;
        int rc;
 
-       tsec = current->cred->security;
        dsec = dir->i_security;
        sbsec = dir->i_sb->s_security;
 
+       sid = tsec->sid;
+       newsid = tsec->create_sid;
+
        AVC_AUDIT_DATA_INIT(&ad, FS);
        ad.u.fs.path.dentry = dentry;
 
-       rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
+       rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
                          DIR__ADD_NAME | DIR__SEARCH,
                          &ad);
        if (rc)
                return rc;
 
-       if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
-               newsid = tsec->create_sid;
-       } else {
-               rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
-                                            &newsid);
+       if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
+               rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
                if (rc)
                        return rc;
        }
 
-       rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
+       rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
        if (rc)
                return rc;
 
@@ -1531,11 +1561,9 @@ static int may_create(struct inode *dir,
 static int may_create_key(u32 ksid,
                          struct task_struct *ctx)
 {
-       struct task_security_struct *tsec;
-
-       tsec = ctx->cred->security;
+       u32 sid = task_sid(ctx);
 
-       return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
+       return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
 }
 
 #define MAY_LINK       0
@@ -1548,13 +1576,12 @@ static int may_link(struct inode *dir,
                    int kind)
 
 {
-       struct task_security_struct *tsec;
        struct inode_security_struct *dsec, *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        u32 av;
        int rc;
 
-       tsec = current->cred->security;
        dsec = dir->i_security;
        isec = dentry->d_inode->i_security;
 
@@ -1563,7 +1590,7 @@ static int may_link(struct inode *dir,
 
        av = DIR__SEARCH;
        av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
-       rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
+       rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
        if (rc)
                return rc;
 
@@ -1583,7 +1610,7 @@ static int may_link(struct inode *dir,
                return 0;
        }
 
-       rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
+       rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
        return rc;
 }
 
@@ -1592,14 +1619,13 @@ static inline int may_rename(struct inode *old_dir,
                             struct inode *new_dir,
                             struct dentry *new_dentry)
 {
-       struct task_security_struct *tsec;
        struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        u32 av;
        int old_is_dir, new_is_dir;
        int rc;
 
-       tsec = current->cred->security;
        old_dsec = old_dir->i_security;
        old_isec = old_dentry->d_inode->i_security;
        old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
@@ -1608,16 +1634,16 @@ static inline int may_rename(struct inode *old_dir,
        AVC_AUDIT_DATA_INIT(&ad, FS);
 
        ad.u.fs.path.dentry = old_dentry;
-       rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
+       rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
                          DIR__REMOVE_NAME | DIR__SEARCH, &ad);
        if (rc)
                return rc;
-       rc = avc_has_perm(tsec->sid, old_isec->sid,
+       rc = avc_has_perm(sid, old_isec->sid,
                          old_isec->sclass, FILE__RENAME, &ad);
        if (rc)
                return rc;
        if (old_is_dir && new_dir != old_dir) {
-               rc = avc_has_perm(tsec->sid, old_isec->sid,
+               rc = avc_has_perm(sid, old_isec->sid,
                                  old_isec->sclass, DIR__REPARENT, &ad);
                if (rc)
                        return rc;
@@ -1627,13 +1653,13 @@ static inline int may_rename(struct inode *old_dir,
        av = DIR__ADD_NAME | DIR__SEARCH;
        if (new_dentry->d_inode)
                av |= DIR__REMOVE_NAME;
-       rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
+       rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
        if (rc)
                return rc;
        if (new_dentry->d_inode) {
                new_isec = new_dentry->d_inode->i_security;
                new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
-               rc = avc_has_perm(tsec->sid, new_isec->sid,
+               rc = avc_has_perm(sid, new_isec->sid,
                                  new_isec->sclass,
                                  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
                if (rc)
@@ -1649,13 +1675,11 @@ static int superblock_has_perm(struct task_struct *tsk,
                               u32 perms,
                               struct avc_audit_data *ad)
 {
-       struct task_security_struct *tsec;
        struct superblock_security_struct *sbsec;
+       u32 sid = task_sid(tsk);
 
-       tsec = tsk->cred->security;
        sbsec = sb->s_security;
-       return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
-                           perms, ad);
+       return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
 }
 
 /* Convert a Linux mode and permission mask to an access vector. */
@@ -1751,10 +1775,9 @@ static int selinux_ptrace_may_access(struct task_struct *child,
                return rc;
 
        if (mode == PTRACE_MODE_READ) {
-               struct task_security_struct *tsec = current->cred->security;
-               struct task_security_struct *csec = child->cred->security;
-               return avc_has_perm(tsec->sid, csec->sid,
-                                   SECCLASS_FILE, FILE__READ, NULL);
+               u32 sid = current_sid();
+               u32 csid = task_sid(child);
+               return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
        }
 
        return task_has_perm(current, child, PROCESS__PTRACE);
@@ -1859,15 +1882,14 @@ static int selinux_sysctl(ctl_table *table, int op)
 {
        int error = 0;
        u32 av;
-       struct task_security_struct *tsec;
-       u32 tsid;
+       u32 tsid, sid;
        int rc;
 
        rc = secondary_ops->sysctl(table, op);
        if (rc)
                return rc;
 
-       tsec = current->cred->security;
+       sid = current_sid();
 
        rc = selinux_sysctl_get_sid(table, (op == 0001) ?
                                    SECCLASS_DIR : SECCLASS_FILE, &tsid);
@@ -1879,7 +1901,7 @@ static int selinux_sysctl(ctl_table *table, int op)
        /* The op values are "defined" in sysctl.c, thereby creating
         * a bad coupling between this module and sysctl.c */
        if (op == 001) {
-               error = avc_has_perm(tsec->sid, tsid,
+               error = avc_has_perm(sid, tsid,
                                     SECCLASS_DIR, DIR__SEARCH, NULL);
        } else {
                av = 0;
@@ -1888,7 +1910,7 @@ static int selinux_sysctl(ctl_table *table, int op)
                if (op & 002)
                        av |= FILE__WRITE;
                if (av)
-                       error = avc_has_perm(tsec->sid, tsid,
+                       error = avc_has_perm(sid, tsid,
                                             SECCLASS_FILE, av, NULL);
        }
 
@@ -2018,7 +2040,7 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm)
        if (bsec->set)
                return 0;
 
-       tsec = current->cred->security;
+       tsec = current_security();
        isec = inode->i_security;
 
        /* Default to the current task SID. */
@@ -2083,14 +2105,19 @@ static int selinux_bprm_check_security(struct linux_binprm *bprm)
 
 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
 {
-       struct task_security_struct *tsec = current->cred->security;
+       const struct cred *cred = current_cred();
+       const struct task_security_struct *tsec = cred->security;
+       u32 sid, osid;
        int atsecure = 0;
 
-       if (tsec->osid != tsec->sid) {
+       sid = tsec->sid;
+       osid = tsec->osid;
+
+       if (osid != sid) {
                /* Enable secure mode for SIDs transitions unless
                   the noatsecure permission is granted between
                   the two SIDs, i.e. ahp returns 0. */
-               atsecure = avc_has_perm(tsec->osid, tsec->sid,
+               atsecure = avc_has_perm(osid, sid,
                                         SECCLASS_PROCESS,
                                         PROCESS__NOATSECURE, NULL);
        }
@@ -2207,7 +2234,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
 
        secondary_ops->bprm_apply_creds(bprm, unsafe);
 
-       tsec = current->cred->security;
+       tsec = current_security();
 
        bsec = bprm->security;
        sid = bsec->sid;
@@ -2236,7 +2263,7 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
                        rcu_read_lock();
                        tracer = tracehook_tracer_task(current);
                        if (likely(tracer != NULL)) {
-                               sec = tracer->cred->security;
+                               sec = __task_cred(tracer)->security;
                                ptsid = sec->sid;
                        }
                        rcu_read_unlock();
@@ -2267,7 +2294,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
        int rc, i;
        unsigned long flags;
 
-       tsec = current->cred->security;
+       tsec = current_security();
        bsec = bprm->security;
 
        if (bsec->unsafe) {
@@ -2507,21 +2534,22 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
                                       char **name, void **value,
                                       size_t *len)
 {
-       struct task_security_struct *tsec;
+       const struct cred *cred = current_cred();
+       const struct task_security_struct *tsec = cred->security;
        struct inode_security_struct *dsec;
        struct superblock_security_struct *sbsec;
-       u32 newsid, clen;
+       u32 sid, newsid, clen;
        int rc;
        char *namep = NULL, *context;
 
-       tsec = current->cred->security;
        dsec = dir->i_security;
        sbsec = dir->i_sb->s_security;
 
-       if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
-               newsid = tsec->create_sid;
-       } else {
-               rc = security_transition_sid(tsec->sid, dsec->sid,
+       sid = tsec->sid;
+       newsid = tsec->create_sid;
+
+       if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
+               rc = security_transition_sid(sid, dsec->sid,
                                             inode_mode_to_security_class(inode->i_mode),
                                             &newsid);
                if (rc) {
@@ -2699,12 +2727,11 @@ static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
                                  const void *value, size_t size, int flags)
 {
-       struct task_security_struct *tsec = current->cred->security;
        struct inode *inode = dentry->d_inode;
        struct inode_security_struct *isec = inode->i_security;
        struct superblock_security_struct *sbsec;
        struct avc_audit_data ad;
-       u32 newsid;
+       u32 newsid, sid = current_sid();
        int rc = 0;
 
        if (strcmp(name, XATTR_NAME_SELINUX))
@@ -2720,7 +2747,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
        AVC_AUDIT_DATA_INIT(&ad, FS);
        ad.u.fs.path.dentry = dentry;
 
-       rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
+       rc = avc_has_perm(sid, isec->sid, isec->sclass,
                          FILE__RELABELFROM, &ad);
        if (rc)
                return rc;
@@ -2734,12 +2761,12 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
        if (rc)
                return rc;
 
-       rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
+       rc = avc_has_perm(sid, newsid, isec->sclass,
                          FILE__RELABELTO, &ad);
        if (rc)
                return rc;
 
-       rc = security_validate_transition(isec->sid, newsid, tsec->sid,
+       rc = security_validate_transition(isec->sid, newsid, sid,
                                          isec->sclass);
        if (rc)
                return rc;
@@ -2911,16 +2938,16 @@ static int selinux_revalidate_file_permission(struct file *file, int mask)
 static int selinux_file_permission(struct file *file, int mask)
 {
        struct inode *inode = file->f_path.dentry->d_inode;
-       struct task_security_struct *tsec = current->cred->security;
        struct file_security_struct *fsec = file->f_security;
        struct inode_security_struct *isec = inode->i_security;
+       u32 sid = current_sid();
 
        if (!mask) {
                /* No permission to check.  Existence test. */
                return 0;
        }
 
-       if (tsec->sid == fsec->sid && fsec->isid == isec->sid
+       if (sid == fsec->sid && fsec->isid == isec->sid
            && fsec->pseqno == avc_policy_seqno())
                return selinux_netlbl_inode_permission(inode, mask);
 
@@ -2988,8 +3015,7 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot,
                             unsigned long addr, unsigned long addr_only)
 {
        int rc = 0;
-       u32 sid = ((struct task_security_struct *)
-                  (current->cred->security))->sid;
+       u32 sid = current_sid();
 
        if (addr < mmap_min_addr)
                rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
@@ -3098,12 +3124,10 @@ static int selinux_file_fcntl(struct file *file, unsigned int cmd,
 
 static int selinux_file_set_fowner(struct file *file)
 {
-       struct task_security_struct *tsec;
        struct file_security_struct *fsec;
 
-       tsec = current->cred->security;
        fsec = file->f_security;
-       fsec->fown_sid = tsec->sid;
+       fsec->fown_sid = current_sid();
 
        return 0;
 }
@@ -3112,14 +3136,13 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk,
                                       struct fown_struct *fown, int signum)
 {
        struct file *file;
+       u32 sid = current_sid();
        u32 perm;
-       struct task_security_struct *tsec;
        struct file_security_struct *fsec;
 
        /* struct fown_struct is never outside the context of a struct file */
        file = container_of(fown, struct file, f_owner);
 
-       tsec = tsk->cred->security;
        fsec = file->f_security;
 
        if (!signum)
@@ -3127,7 +3150,7 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk,
        else
                perm = signal_to_av(signum);
 
-       return avc_has_perm(fsec->fown_sid, tsec->sid,
+       return avc_has_perm(fsec->fown_sid, sid,
                            SECCLASS_PROCESS, perm, NULL);
 }
 
@@ -3182,7 +3205,7 @@ static int selinux_cred_alloc_security(struct cred *cred)
        struct task_security_struct *tsec1, *tsec2;
        int rc;
 
-       tsec1 = current->cred->security;
+       tsec1 = current_security();
 
        rc = cred_alloc_security(cred);
        if (rc)
@@ -3250,8 +3273,7 @@ static int selinux_task_getsid(struct task_struct *p)
 
 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
 {
-       struct task_security_struct *tsec = p->cred->security;
-       *secid = tsec->sid;
+       *secid = task_sid(p);
 }
 
 static int selinux_task_setgroups(struct group_info *group_info)
@@ -3332,7 +3354,6 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
 {
        u32 perm;
        int rc;
-       struct task_security_struct *tsec;
 
        rc = secondary_ops->task_kill(p, info, sig, secid);
        if (rc)
@@ -3342,9 +3363,9 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
                perm = PROCESS__SIGNULL; /* null signal; existence test */
        else
                perm = signal_to_av(sig);
-       tsec = p->cred->security;
        if (secid)
-               rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL);
+               rc = avc_has_perm(secid, task_sid(p),
+                                 SECCLASS_PROCESS, perm, NULL);
        else
                rc = task_has_perm(current, p, perm);
        return rc;
@@ -3383,12 +3404,11 @@ static void selinux_task_reparent_to_init(struct task_struct *p)
 static void selinux_task_to_inode(struct task_struct *p,
                                  struct inode *inode)
 {
-       struct task_security_struct *tsec = p->cred->security;
        struct inode_security_struct *isec = inode->i_security;
+       u32 sid = task_sid(p);
 
-       isec->sid = tsec->sid;
+       isec->sid = sid;
        isec->initialized = 1;
-       return;
 }
 
 /* Returns error only if unable to parse addresses */
@@ -3627,19 +3647,19 @@ static int socket_has_perm(struct task_struct *task, struct socket *sock,
                           u32 perms)
 {
        struct inode_security_struct *isec;
-       struct task_security_struct *tsec;
        struct avc_audit_data ad;
+       u32 sid;
        int err = 0;
 
-       tsec = task->cred->security;
        isec = SOCK_INODE(sock)->i_security;
 
        if (isec->sid == SECINITSID_KERNEL)
                goto out;
+       sid = task_sid(task);
 
        AVC_AUDIT_DATA_INIT(&ad, NET);
        ad.u.net.sk = sock->sk;
-       err = avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
+       err = avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
 
 out:
        return err;
@@ -3648,18 +3668,20 @@ out:
 static int selinux_socket_create(int family, int type,
                                 int protocol, int kern)
 {
+       const struct cred *cred = current_cred();
+       const struct task_security_struct *tsec = cred->security;
+       u32 sid, newsid;
+       u16 secclass;
        int err = 0;
-       struct task_security_struct *tsec;
-       u32 newsid;
 
        if (kern)
                goto out;
 
-       tsec = current->cred->security;
-       newsid = tsec->sockcreate_sid ? : tsec->sid;
-       err = avc_has_perm(tsec->sid, newsid,
-                          socket_type_to_security_class(family, type,
-                          protocol), SOCKET__CREATE, NULL);
+       sid = tsec->sid;
+       newsid = tsec->sockcreate_sid ?sid;
+
+       secclass = socket_type_to_security_class(family, type, protocol);
+       err = avc_has_perm(sid, newsid, secclass, SOCKET__CREATE, NULL);
 
 out:
        return err;
@@ -3668,18 +3690,26 @@ out:
 static int selinux_socket_post_create(struct socket *sock, int family,
                                      int type, int protocol, int kern)
 {
-       int err = 0;
+       const struct cred *cred = current_cred();
+       const struct task_security_struct *tsec = cred->security;
        struct inode_security_struct *isec;
-       struct task_security_struct *tsec;
        struct sk_security_struct *sksec;
-       u32 newsid;
+       u32 sid, newsid;
+       int err = 0;
+
+       sid = tsec->sid;
+       newsid = tsec->sockcreate_sid;
 
        isec = SOCK_INODE(sock)->i_security;
 
-       tsec = current->cred->security;
-       newsid = tsec->sockcreate_sid ? : tsec->sid;
+       if (kern)
+               isec->sid = SECINITSID_KERNEL;
+       else if (newsid)
+               isec->sid = newsid;
+       else
+               isec->sid = sid;
+
        isec->sclass = socket_type_to_security_class(family, type, protocol);
-       isec->sid = kern ? SECINITSID_KERNEL : newsid;
        isec->initialized = 1;
 
        if (sock->sk) {
@@ -3714,7 +3744,6 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
        if (family == PF_INET || family == PF_INET6) {
                char *addrp;
                struct inode_security_struct *isec;
-               struct task_security_struct *tsec;
                struct avc_audit_data ad;
                struct sockaddr_in *addr4 = NULL;
                struct sockaddr_in6 *addr6 = NULL;
@@ -3722,7 +3751,6 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
                struct sock *sk = sock->sk;
                u32 sid, node_perm;
 
-               tsec = current->cred->security;
                isec = SOCK_INODE(sock)->i_security;
 
                if (family == PF_INET) {
@@ -4763,15 +4791,16 @@ static int ipc_alloc_security(struct task_struct *task,
                              struct kern_ipc_perm *perm,
                              u16 sclass)
 {
-       struct task_security_struct *tsec = task->cred->security;
        struct ipc_security_struct *isec;
+       u32 sid;
 
        isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
        if (!isec)
                return -ENOMEM;
 
+       sid = task_sid(task);
        isec->sclass = sclass;
-       isec->sid = tsec->sid;
+       isec->sid = sid;
        perm->security = isec;
 
        return 0;
@@ -4809,17 +4838,16 @@ static void msg_msg_free_security(struct msg_msg *msg)
 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
                        u32 perms)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
 
-       tsec = current->cred->security;
        isec = ipc_perms->security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = ipc_perms->key;
 
-       return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
+       return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
 }
 
 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
@@ -4835,22 +4863,21 @@ static void selinux_msg_msg_free_security(struct msg_msg *msg)
 /* message queue security operations */
 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        int rc;
 
        rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
        if (rc)
                return rc;
 
-       tsec = current->cred->security;
        isec = msq->q_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = msq->q_perm.key;
 
-       rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
+       rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
                          MSGQ__CREATE, &ad);
        if (rc) {
                ipc_free_security(&msq->q_perm);
@@ -4866,17 +4893,16 @@ static void selinux_msg_queue_free_security(struct msg_queue *msq)
 
 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
 
-       tsec = current->cred->security;
        isec = msq->q_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = msq->q_perm.key;
 
-       return avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
+       return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
                            MSGQ__ASSOCIATE, &ad);
 }
 
@@ -4910,13 +4936,12 @@ static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
 
 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct msg_security_struct *msec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        int rc;
 
-       tsec = current->cred->security;
        isec = msq->q_perm.security;
        msec = msg->security;
 
@@ -4928,9 +4953,7 @@ static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
                 * Compute new sid based on current process and
                 * message queue this message will be stored in
                 */
-               rc = security_transition_sid(tsec->sid,
-                                            isec->sid,
-                                            SECCLASS_MSG,
+               rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
                                             &msec->sid);
                if (rc)
                        return rc;
@@ -4940,16 +4963,16 @@ static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
        ad.u.ipc_id = msq->q_perm.key;
 
        /* Can this process write to the queue? */
-       rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
+       rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
                          MSGQ__WRITE, &ad);
        if (!rc)
                /* Can this process send the message */
-               rc = avc_has_perm(tsec->sid, msec->sid,
-                                 SECCLASS_MSG, MSG__SEND, &ad);
+               rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
+                                 MSG__SEND, &ad);
        if (!rc)
                /* Can the message be put in the queue? */
-               rc = avc_has_perm(msec->sid, isec->sid,
-                                 SECCLASS_MSGQ, MSGQ__ENQUEUE, &ad);
+               rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
+                                 MSGQ__ENQUEUE, &ad);
 
        return rc;
 }
@@ -4958,23 +4981,22 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
                                    struct task_struct *target,
                                    long type, int mode)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct msg_security_struct *msec;
        struct avc_audit_data ad;
+       u32 sid = task_sid(target);
        int rc;
 
-       tsec = target->cred->security;
        isec = msq->q_perm.security;
        msec = msg->security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = msq->q_perm.key;
 
-       rc = avc_has_perm(tsec->sid, isec->sid,
+       rc = avc_has_perm(sid, isec->sid,
                          SECCLASS_MSGQ, MSGQ__READ, &ad);
        if (!rc)
-               rc = avc_has_perm(tsec->sid, msec->sid,
+               rc = avc_has_perm(sid, msec->sid,
                                  SECCLASS_MSG, MSG__RECEIVE, &ad);
        return rc;
 }
@@ -4982,22 +5004,21 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
 /* Shared Memory security operations */
 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        int rc;
 
        rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
        if (rc)
                return rc;
 
-       tsec = current->cred->security;
        isec = shp->shm_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = shp->shm_perm.key;
 
-       rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
+       rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
                          SHM__CREATE, &ad);
        if (rc) {
                ipc_free_security(&shp->shm_perm);
@@ -5013,17 +5034,16 @@ static void selinux_shm_free_security(struct shmid_kernel *shp)
 
 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
 
-       tsec = current->cred->security;
        isec = shp->shm_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = shp->shm_perm.key;
 
-       return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
+       return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
                            SHM__ASSOCIATE, &ad);
 }
 
@@ -5081,22 +5101,21 @@ static int selinux_shm_shmat(struct shmid_kernel *shp,
 /* Semaphore security operations */
 static int selinux_sem_alloc_security(struct sem_array *sma)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
        int rc;
 
        rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
        if (rc)
                return rc;
 
-       tsec = current->cred->security;
        isec = sma->sem_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = sma->sem_perm.key;
 
-       rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
+       rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
                          SEM__CREATE, &ad);
        if (rc) {
                ipc_free_security(&sma->sem_perm);
@@ -5112,17 +5131,16 @@ static void selinux_sem_free_security(struct sem_array *sma)
 
 static int selinux_sem_associate(struct sem_array *sma, int semflg)
 {
-       struct task_security_struct *tsec;
        struct ipc_security_struct *isec;
        struct avc_audit_data ad;
+       u32 sid = current_sid();
 
-       tsec = current->cred->security;
        isec = sma->sem_perm.security;
 
        AVC_AUDIT_DATA_INIT(&ad, IPC);
        ad.u.ipc_id = sma->sem_perm.key;
 
-       return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
+       return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
                            SEM__ASSOCIATE, &ad);
 }
 
@@ -5212,7 +5230,7 @@ static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
 static int selinux_getprocattr(struct task_struct *p,
                               char *name, char **value)
 {
-       struct task_security_struct *tsec;
+       const struct task_security_struct *__tsec;
        u32 sid;
        int error;
        unsigned len;
@@ -5223,22 +5241,24 @@ static int selinux_getprocattr(struct task_struct *p,
                        return error;
        }
 
-       tsec = p->cred->security;
+       rcu_read_lock();
+       __tsec = __task_cred(p)->security;
 
        if (!strcmp(name, "current"))
-               sid = tsec->sid;
+               sid = __tsec->sid;
        else if (!strcmp(name, "prev"))
-               sid = tsec->osid;
+               sid = __tsec->osid;
        else if (!strcmp(name, "exec"))
-               sid = tsec->exec_sid;
+               sid = __tsec->exec_sid;
        else if (!strcmp(name, "fscreate"))
-               sid = tsec->create_sid;
+               sid = __tsec->create_sid;
        else if (!strcmp(name, "keycreate"))
-               sid = tsec->keycreate_sid;
+               sid = __tsec->keycreate_sid;
        else if (!strcmp(name, "sockcreate"))
-               sid = tsec->sockcreate_sid;
+               sid = __tsec->sockcreate_sid;
        else
-               return -EINVAL;
+               goto invalid;
+       rcu_read_unlock();
 
        if (!sid)
                return 0;
@@ -5247,6 +5267,10 @@ static int selinux_getprocattr(struct task_struct *p,
        if (error)
                return error;
        return len;
+
+invalid:
+       rcu_read_unlock();
+       return -EINVAL;
 }
 
 static int selinux_setprocattr(struct task_struct *p,
@@ -5360,9 +5384,7 @@ boundary_ok:
                rcu_read_lock();
                tracer = tracehook_tracer_task(p);
                if (tracer != NULL) {
-                       struct task_security_struct *ptsec =
-                               tracer->cred->security;
-                       u32 ptsid = ptsec->sid;
+                       u32 ptsid = task_sid(tracer);
                        rcu_read_unlock();
                        error = avc_has_perm_noaudit(ptsid, sid,
                                                     SECCLASS_PROCESS,
@@ -5405,19 +5427,22 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
 static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
                             unsigned long flags)
 {
-       struct task_security_struct *tsec = tsk->cred->security;
+       const struct task_security_struct *__tsec;
        struct key_security_struct *ksec;
 
        ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
        if (!ksec)
                return -ENOMEM;
 
-       if (tsec->keycreate_sid)
-               ksec->sid = tsec->keycreate_sid;
+       rcu_read_lock();
+       __tsec = __task_cred(tsk)->security;
+       if (__tsec->keycreate_sid)
+               ksec->sid = __tsec->keycreate_sid;
        else
-               ksec->sid = tsec->sid;
-       k->security = ksec;
+               ksec->sid = __tsec->sid;
+       rcu_read_unlock();
 
+       k->security = ksec;
        return 0;
 }
 
@@ -5434,13 +5459,8 @@ static int selinux_key_permission(key_ref_t key_ref,
                            key_perm_t perm)
 {
        struct key *key;
-       struct task_security_struct *tsec;
        struct key_security_struct *ksec;
-
-       key = key_ref_to_ptr(key_ref);
-
-       tsec = ctx->cred->security;
-       ksec = key->security;
+       u32 sid;
 
        /* if no specific permissions are requested, we skip the
           permission check. No serious, additional covert channels
@@ -5448,8 +5468,12 @@ static int selinux_key_permission(key_ref_t key_ref,
        if (perm == 0)
                return 0;
 
-       return avc_has_perm(tsec->sid, ksec->sid,
-                           SECCLASS_KEY, perm, NULL);
+       sid = task_sid(ctx);
+
+       key = key_ref_to_ptr(key_ref);
+       ksec = key->security;
+
+       return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
 }
 
 static int selinux_key_getsecurity(struct key *key, char **_buffer)