Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (105 commits)
  SELinux: don't check permissions for kernel mounts
  security: pass mount flags to security_sb_kern_mount()
  SELinux: correctly detect proc filesystems of the form "proc/foo"
  Audit: Log TIOCSTI
  user namespaces: document CFS behavior
  user namespaces: require cap_set{ug}id for CLONE_NEWUSER
  user namespaces: let user_ns be cloned with fairsched
  CRED: fix sparse warnings
  User namespaces: use the current_user_ns() macro
  User namespaces: set of cleanups (v2)
  nfsctl: add headers for credentials
  coda: fix creds reference
  capabilities: define get_vfs_caps_from_disk when file caps are not enabled
  CRED: Allow kernel services to override LSM settings for task actions
  CRED: Add a kernel_service object class to SELinux
  CRED: Differentiate objective and effective subjective credentials on a task
  CRED: Documentation
  CRED: Use creds in file structs
  CRED: Prettify commoncap.c
  CRED: Make execve() take advantage of copy-on-write credentials
  ...

1 files changed, 332 insertions, 254 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index 31deba8f7d16..ebe65c2c9873 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -112,12 +112,17 @@ EXPORT_SYMBOL(cad_pid);
 
 void (*pm_power_off_prepare)(void);
 
+/*
+ * set the priority of a task
+ * - the caller must hold the RCU read lock
+ */
 static int set_one_prio(struct task_struct *p, int niceval, int error)
 {
+        const struct cred *cred = current_cred(), *pcred = __task_cred(p);
         int no_nice;
 
-        if (p->uid != current->euid &&
-                p->euid != current->euid && !capable(CAP_SYS_NICE)) {
+        if (pcred->uid  != cred->euid &&
+            pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
                 error = -EPERM;
                 goto out;
         }
@@ -141,6 +146,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
 {
         struct task_struct *g, *p;
         struct user_struct *user;
+        const struct cred *cred = current_cred();
         int error = -EINVAL;
         struct pid *pgrp;
 
@@ -174,18 +180,18 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        user = current->user;
+                        user = (struct user_struct *) cred->user;
                         if (!who)
-                                who = current->uid;
-                        else
-                                if ((who != current->uid) && !(user = find_user(who)))
-                                        goto out_unlock;        /* No processes for this user */
+                                who = cred->uid;
+                        else if ((who != cred->uid) &&
+                                 !(user = find_user(who)))
+                                goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p)
-                                if (p->uid == who)
+                                if (__task_cred(p)->uid == who)
                                         error = set_one_prio(p, niceval, error);
                         while_each_thread(g, p);
-                        if (who != current->uid)
+                        if (who != cred->uid)
                                 free_uid(user);         /* For find_user() */
                         break;
         }
@@ -205,6 +211,7 @@ asmlinkage long sys_getpriority(int which, int who)
 {
         struct task_struct *g, *p;
         struct user_struct *user;
+        const struct cred *cred = current_cred();
         long niceval, retval = -ESRCH;
         struct pid *pgrp;
 
@@ -236,21 +243,21 @@ asmlinkage long sys_getpriority(int which, int who)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        user = current->user;
+                        user = (struct user_struct *) cred->user;
                         if (!who)
-                                who = current->uid;
-                        else
-                                if ((who != current->uid) && !(user = find_user(who)))
-                                        goto out_unlock;        /* No processes for this user */
+                                who = cred->uid;
+                        else if ((who != cred->uid) &&
+                                 !(user = find_user(who)))
+                                goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p)
-                                if (p->uid == who) {
+                                if (__task_cred(p)->uid == who) {
                                         niceval = 20 - task_nice(p);
                                         if (niceval > retval)
                                                 retval = niceval;
                                 }
                         while_each_thread(g, p);
-                        if (who != current->uid)
+                        if (who != cred->uid)
                                 free_uid(user);         /* for find_user() */
                         break;
         }
@@ -472,46 +479,48 @@ void ctrl_alt_del(void)
  */
 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 {
-        int old_rgid = current->gid;
-        int old_egid = current->egid;
-        int new_rgid = old_rgid;
-        int new_egid = old_egid;
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+        old = current_cred();
+
         retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
         if (retval)
-                return retval;
+                goto error;
 
+        retval = -EPERM;
         if (rgid != (gid_t) -1) {
-                if ((old_rgid == rgid) ||
-                    (current->egid==rgid) ||
+                if (old->gid == rgid ||
+                    old->egid == rgid ||
                     capable(CAP_SETGID))
-                        new_rgid = rgid;
+                        new->gid = rgid;
                 else
-                        return -EPERM;
+                        goto error;
         }
         if (egid != (gid_t) -1) {
-                if ((old_rgid == egid) ||
-                    (current->egid == egid) ||
-                    (current->sgid == egid) ||
+                if (old->gid == egid ||
+                    old->egid == egid ||
+                    old->sgid == egid ||
                     capable(CAP_SETGID))
-                        new_egid = egid;
+                        new->egid = egid;
                 else
-                        return -EPERM;
-        }
-        if (new_egid != old_egid) {
-                set_dumpable(current->mm, suid_dumpable);
-                smp_wmb();
+                        goto error;
         }
+
         if (rgid != (gid_t) -1 ||
-            (egid != (gid_t) -1 && egid != old_rgid))
-                current->sgid = new_egid;
-        current->fsgid = new_egid;
-        current->egid = new_egid;
-        current->gid = new_rgid;
-        key_fsgid_changed(current);
-        proc_id_connector(current, PROC_EVENT_GID);
-        return 0;
+            (egid != (gid_t) -1 && egid != old->gid))
+                new->sgid = new->egid;
+        new->fsgid = new->egid;
+
+        return commit_creds(new);
+
+error:
+        abort_creds(new);
+        return retval;
 }
 
 /*
@@ -521,56 +530,54 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
  */
 asmlinkage long sys_setgid(gid_t gid)
 {
-        int old_egid = current->egid;
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+        old = current_cred();
+
         retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
         if (retval)
-                return retval;
+                goto error;
 
-        if (capable(CAP_SETGID)) {
-                if (old_egid != gid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                current->gid = current->egid = current->sgid = current->fsgid = gid;
-        } else if ((gid == current->gid) || (gid == current->sgid)) {
-                if (old_egid != gid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                current->egid = current->fsgid = gid;
-        }
+        retval = -EPERM;
+        if (capable(CAP_SETGID))
+                new->gid = new->egid = new->sgid = new->fsgid = gid;
+        else if (gid == old->gid || gid == old->sgid)
+                new->egid = new->fsgid = gid;
         else
-                return -EPERM;
+                goto error;
 
-        key_fsgid_changed(current);
-        proc_id_connector(current, PROC_EVENT_GID);
-        return 0;
+        return commit_creds(new);
+
+error:
+        abort_creds(new);
+        return retval;
 }
   
-static int set_user(uid_t new_ruid, int dumpclear)
+/*
+ * change the user struct in a credentials set to match the new UID
+ */
+static int set_user(struct cred *new)
 {
         struct user_struct *new_user;
 
-        new_user = alloc_uid(current->nsproxy->user_ns, new_ruid);
+        new_user = alloc_uid(current_user_ns(), new->uid);
         if (!new_user)
                 return -EAGAIN;
 
         if (atomic_read(&new_user->processes) >=
                                 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
-                        new_user != current->nsproxy->user_ns->root_user) {
+                        new_user != INIT_USER) {
                 free_uid(new_user);
                 return -EAGAIN;
         }
 
-        switch_uid(new_user);
-
-        if (dumpclear) {
-                set_dumpable(current->mm, suid_dumpable);
-                smp_wmb();
-        }
-        current->uid = new_ruid;
+        free_uid(new->user);
+        new->user = new_user;
         return 0;
 }
 
@@ -591,54 +598,56 @@ static int set_user(uid_t new_ruid, int dumpclear)
  */
 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 {
-        int old_ruid, old_euid, old_suid, new_ruid, new_euid;
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+        old = current_cred();
+
         retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
         if (retval)
-                return retval;
-
-        new_ruid = old_ruid = current->uid;
-        new_euid = old_euid = current->euid;
-        old_suid = current->suid;
+                goto error;
 
+        retval = -EPERM;
         if (ruid != (uid_t) -1) {
-                new_ruid = ruid;
-                if ((old_ruid != ruid) &&
-                    (current->euid != ruid) &&
+                new->uid = ruid;
+                if (old->uid != ruid &&
+                    old->euid != ruid &&
                     !capable(CAP_SETUID))
-                        return -EPERM;
+                        goto error;
         }
 
         if (euid != (uid_t) -1) {
-                new_euid = euid;
-                if ((old_ruid != euid) &&
-                    (current->euid != euid) &&
-                    (current->suid != euid) &&
+                new->euid = euid;
+                if (old->uid != euid &&
+                    old->euid != euid &&
+                    old->suid != euid &&
                     !capable(CAP_SETUID))
-                        return -EPERM;
+                        goto error;
         }
 
-        if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
-                return -EAGAIN;
+        retval = -EAGAIN;
+        if (new->uid != old->uid && set_user(new) < 0)
+                goto error;
 
-        if (new_euid != old_euid) {
-                set_dumpable(current->mm, suid_dumpable);
-                smp_wmb();
-        }
-        current->fsuid = current->euid = new_euid;
         if (ruid != (uid_t) -1 ||
-            (euid != (uid_t) -1 && euid != old_ruid))
-                current->suid = current->euid;
-        current->fsuid = current->euid;
+            (euid != (uid_t) -1 && euid != old->uid))
+                new->suid = new->euid;
+        new->fsuid = new->euid;
 
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
-
-        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
-}
+        retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
+        if (retval < 0)
+                goto error;
 
+        return commit_creds(new);
 
+error:
+        abort_creds(new);
+        return retval;
+}
                 
 /*
  * setuid() is implemented like SysV with SAVED_IDS 
@@ -653,36 +662,41 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
  */
 asmlinkage long sys_setuid(uid_t uid)
 {
-        int old_euid = current->euid;
-        int old_ruid, old_suid, new_suid;
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+        old = current_cred();
+
         retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
         if (retval)
-                return retval;
+                goto error;
 
-        old_ruid = current->uid;
-        old_suid = current->suid;
-        new_suid = old_suid;
-        
+        retval = -EPERM;
         if (capable(CAP_SETUID)) {
-                if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
-                        return -EAGAIN;
-                new_suid = uid;
-        } else if ((uid != current->uid) && (uid != new_suid))
-                return -EPERM;
-
-        if (old_euid != uid) {
-                set_dumpable(current->mm, suid_dumpable);
-                smp_wmb();
+                new->suid = new->uid = uid;
+                if (uid != old->uid && set_user(new) < 0) {
+                        retval = -EAGAIN;
+                        goto error;
+                }
+        } else if (uid != old->uid && uid != new->suid) {
+                goto error;
         }
-        current->fsuid = current->euid = uid;
-        current->suid = new_suid;
 
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
+        new->fsuid = new->euid = uid;
+
+        retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
+        if (retval < 0)
+                goto error;
 
-        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
+        return commit_creds(new);
+
+error:
+        abort_creds(new);
+        return retval;
 }
 
 
@@ -692,54 +706,63 @@ asmlinkage long sys_setuid(uid_t uid)
  */
 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-        int old_ruid = current->uid;
-        int old_euid = current->euid;
-        int old_suid = current->suid;
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+
         retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
         if (retval)
-                return retval;
+                goto error;
+        old = current_cred();
 
+        retval = -EPERM;
         if (!capable(CAP_SETUID)) {
-                if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
-                    (ruid != current->euid) && (ruid != current->suid))
-                        return -EPERM;
-                if ((euid != (uid_t) -1) && (euid != current->uid) &&
-                    (euid != current->euid) && (euid != current->suid))
-                        return -EPERM;
-                if ((suid != (uid_t) -1) && (suid != current->uid) &&
-                    (suid != current->euid) && (suid != current->suid))
-                        return -EPERM;
+                if (ruid != (uid_t) -1 && ruid != old->uid &&
+                    ruid != old->euid  && ruid != old->suid)
+                        goto error;
+                if (euid != (uid_t) -1 && euid != old->uid &&
+                    euid != old->euid  && euid != old->suid)
+                        goto error;
+                if (suid != (uid_t) -1 && suid != old->uid &&
+                    suid != old->euid  && suid != old->suid)
+                        goto error;
         }
+
+        retval = -EAGAIN;
         if (ruid != (uid_t) -1) {
-                if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
-                        return -EAGAIN;
+                new->uid = ruid;
+                if (ruid != old->uid && set_user(new) < 0)
+                        goto error;
         }
-        if (euid != (uid_t) -1) {
-                if (euid != current->euid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                current->euid = euid;
-        }
-        current->fsuid = current->euid;
+        if (euid != (uid_t) -1)
+                new->euid = euid;
         if (suid != (uid_t) -1)
-                current->suid = suid;
+                new->suid = suid;
+        new->fsuid = new->euid;
+
+        retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
+        if (retval < 0)
+                goto error;
 
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
+        return commit_creds(new);
 
-        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
+error:
+        abort_creds(new);
+        return retval;
 }
 
 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
 {
+        const struct cred *cred = current_cred();
         int retval;
 
-        if (!(retval = put_user(current->uid, ruid)) &&
-            !(retval = put_user(current->euid, euid)))
-                retval = put_user(current->suid, suid);
+        if (!(retval   = put_user(cred->uid,  ruid)) &&
+            !(retval   = put_user(cred->euid, euid)))
+                retval = put_user(cred->suid, suid);
 
         return retval;
 }
@@ -749,48 +772,55 @@ asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __us
  */
 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 {
+        const struct cred *old;
+        struct cred *new;
         int retval;
 
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+        old = current_cred();
+
         retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
         if (retval)
-                return retval;
+                goto error;
 
+        retval = -EPERM;
         if (!capable(CAP_SETGID)) {
-                if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
-                    (rgid != current->egid) && (rgid != current->sgid))
-                        return -EPERM;
-                if ((egid != (gid_t) -1) && (egid != current->gid) &&
-                    (egid != current->egid) && (egid != current->sgid))
-                        return -EPERM;
-                if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
-                    (sgid != current->egid) && (sgid != current->sgid))
-                        return -EPERM;
+                if (rgid != (gid_t) -1 && rgid != old->gid &&
+                    rgid != old->egid  && rgid != old->sgid)
+                        goto error;
+                if (egid != (gid_t) -1 && egid != old->gid &&
+                    egid != old->egid  && egid != old->sgid)
+                        goto error;
+                if (sgid != (gid_t) -1 && sgid != old->gid &&
+                    sgid != old->egid  && sgid != old->sgid)
+                        goto error;
         }
-        if (egid != (gid_t) -1) {
-                if (egid != current->egid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                current->egid = egid;
-        }
-        current->fsgid = current->egid;
+
         if (rgid != (gid_t) -1)
-                current->gid = rgid;
+                new->gid = rgid;
+        if (egid != (gid_t) -1)
+                new->egid = egid;
         if (sgid != (gid_t) -1)
-                current->sgid = sgid;
+                new->sgid = sgid;
+        new->fsgid = new->egid;
 
-        key_fsgid_changed(current);
-        proc_id_connector(current, PROC_EVENT_GID);
-        return 0;
+        return commit_creds(new);
+
+error:
+        abort_creds(new);
+        return retval;
 }
 
 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
 {
+        const struct cred *cred = current_cred();
         int retval;
 
-        if (!(retval = put_user(current->gid, rgid)) &&
-            !(retval = put_user(current->egid, egid)))
-                retval = put_user(current->sgid, sgid);
+        if (!(retval   = put_user(cred->gid,  rgid)) &&
+            !(retval   = put_user(cred->egid, egid)))
+                retval = put_user(cred->sgid, sgid);
 
         return retval;
 }
@@ -804,27 +834,35 @@ asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __us
  */
 asmlinkage long sys_setfsuid(uid_t uid)
 {
-        int old_fsuid;
+        const struct cred *old;
+        struct cred *new;
+        uid_t old_fsuid;
 
-        old_fsuid = current->fsuid;
-        if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
-                return old_fsuid;
+        new = prepare_creds();
+        if (!new)
+                return current_fsuid();
+        old = current_cred();
+        old_fsuid = old->fsuid;
 
-        if (uid == current->uid || uid == current->euid ||
-            uid == current->suid || uid == current->fsuid || 
+        if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
+                goto error;
+
+        if (uid == old->uid  || uid == old->euid  ||
+            uid == old->suid || uid == old->fsuid ||
             capable(CAP_SETUID)) {
                 if (uid != old_fsuid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
+                        new->fsuid = uid;
+                        if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
+                                goto change_okay;
                 }
-                current->fsuid = uid;
         }
 
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
-
-        security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
+error:
+        abort_creds(new);
+        return old_fsuid;
 
+change_okay:
+        commit_creds(new);
         return old_fsuid;
 }
 
@@ -833,23 +871,34 @@ asmlinkage long sys_setfsuid(uid_t uid)
  */
 asmlinkage long sys_setfsgid(gid_t gid)
 {
-        int old_fsgid;
+        const struct cred *old;
+        struct cred *new;
+        gid_t old_fsgid;
+
+        new = prepare_creds();
+        if (!new)
+                return current_fsgid();
+        old = current_cred();
+        old_fsgid = old->fsgid;
 
-        old_fsgid = current->fsgid;
         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
-                return old_fsgid;
+                goto error;
 
-        if (gid == current->gid || gid == current->egid ||
-            gid == current->sgid || gid == current->fsgid || 
+        if (gid == old->gid  || gid == old->egid  ||
+            gid == old->sgid || gid == old->fsgid ||
             capable(CAP_SETGID)) {
                 if (gid != old_fsgid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
+                        new->fsgid = gid;
+                        goto change_okay;
                 }
-                current->fsgid = gid;
-                key_fsgid_changed(current);
-                proc_id_connector(current, PROC_EVENT_GID);
         }
+
+error:
+        abort_creds(new);
+        return old_fsgid;
+
+change_okay:
+        commit_creds(new);
         return old_fsgid;
 }
 
@@ -1118,7 +1167,7 @@ EXPORT_SYMBOL(groups_free);
 
 /* export the group_info to a user-space array */
 static int groups_to_user(gid_t __user *grouplist,
-    struct group_info *group_info)
+                          const struct group_info *group_info)
 {
         int i;
         unsigned int count = group_info->ngroups;
@@ -1186,7 +1235,7 @@ static void groups_sort(struct group_info *group_info)
 }
 
 /* a simple bsearch */
-int groups_search(struct group_info *group_info, gid_t grp)
+int groups_search(const struct group_info *group_info, gid_t grp)
 {
         unsigned int left, right;
 
@@ -1208,51 +1257,74 @@ int groups_search(struct group_info *group_info, gid_t grp)
         return 0;
 }
 
-/* validate and set current->group_info */
-int set_current_groups(struct group_info *group_info)
+/**
+ * set_groups - Change a group subscription in a set of credentials
+ * @new: The newly prepared set of credentials to alter
+ * @group_info: The group list to install
+ *
+ * Validate a group subscription and, if valid, insert it into a set
+ * of credentials.
+ */
+int set_groups(struct cred *new, struct group_info *group_info)
 {
         int retval;
-        struct group_info *old_info;
 
         retval = security_task_setgroups(group_info);
         if (retval)
                 return retval;
 
+        put_group_info(new->group_info);
         groups_sort(group_info);
         get_group_info(group_info);
+        new->group_info = group_info;
+        return 0;
+}
+
+EXPORT_SYMBOL(set_groups);
 
-        task_lock(current);
-        old_info = current->group_info;
-        current->group_info = group_info;
-        task_unlock(current);
+/**
+ * set_current_groups - Change current's group subscription
+ * @group_info: The group list to impose
+ *
+ * Validate a group subscription and, if valid, impose it upon current's task
+ * security record.
+ */
+int set_current_groups(struct group_info *group_info)
+{
+        struct cred *new;
+        int ret;
 
-        put_group_info(old_info);
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
 
-        return 0;
+        ret = set_groups(new, group_info);
+        if (ret < 0) {
+                abort_creds(new);
+                return ret;
+        }
+
+        return commit_creds(new);
 }
 
 EXPORT_SYMBOL(set_current_groups);
 
 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
 {
-        int i = 0;
-
-        /*
-         *      SMP: Nobody else can change our grouplist. Thus we are
-         *      safe.
-         */
+        const struct cred *cred = current_cred();
+        int i;
 
         if (gidsetsize < 0)
                 return -EINVAL;
 
         /* no need to grab task_lock here; it cannot change */
-        i = current->group_info->ngroups;
+        i = cred->group_info->ngroups;
         if (gidsetsize) {
                 if (i > gidsetsize) {
                         i = -EINVAL;
                         goto out;
                 }
-                if (groups_to_user(grouplist, current->group_info)) {
+                if (groups_to_user(grouplist, cred->group_info)) {
                         i = -EFAULT;
                         goto out;
                 }
@@ -1296,9 +1368,11 @@ asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
  */
 int in_group_p(gid_t grp)
 {
+        const struct cred *cred = current_cred();
         int retval = 1;
-        if (grp != current->fsgid)
-                retval = groups_search(current->group_info, grp);
+
+        if (grp != cred->fsgid)
+                retval = groups_search(cred->group_info, grp);
         return retval;
 }
 
@@ -1306,9 +1380,11 @@ EXPORT_SYMBOL(in_group_p);
 
 int in_egroup_p(gid_t grp)
 {
+        const struct cred *cred = current_cred();
         int retval = 1;
-        if (grp != current->egid)
-                retval = groups_search(current->group_info, grp);
+
+        if (grp != cred->egid)
+                retval = groups_search(cred->group_info, grp);
         return retval;
 }
 
@@ -1624,50 +1700,56 @@ asmlinkage long sys_umask(int mask)
 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                           unsigned long arg4, unsigned long arg5)
 {
-        long error = 0;
+        struct task_struct *me = current;
+        unsigned char comm[sizeof(me->comm)];
+        long error;
 
-        if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error))
+        error = security_task_prctl(option, arg2, arg3, arg4, arg5);
+        if (error != -ENOSYS)
                 return error;
 
+        error = 0;
         switch (option) {
                 case PR_SET_PDEATHSIG:
                         if (!valid_signal(arg2)) {
                                 error = -EINVAL;
                                 break;
                         }
-                        current->pdeath_signal = arg2;
+                        me->pdeath_signal = arg2;
+                        error = 0;
                         break;
                 case PR_GET_PDEATHSIG:
-                        error = put_user(current->pdeath_signal, (int __user *)arg2);
+                        error = put_user(me->pdeath_signal, (int __user *)arg2);
                         break;
                 case PR_GET_DUMPABLE:
-                        error = get_dumpable(current->mm);
+                        error = get_dumpable(me->mm);
                         break;
                 case PR_SET_DUMPABLE:
                         if (arg2 < 0 || arg2 > 1) {
                                 error = -EINVAL;
                                 break;
                         }
-                        set_dumpable(current->mm, arg2);
+                        set_dumpable(me->mm, arg2);
+                        error = 0;
                         break;
 
                 case PR_SET_UNALIGN:
-                        error = SET_UNALIGN_CTL(current, arg2);
+                        error = SET_UNALIGN_CTL(me, arg2);
                         break;
                 case PR_GET_UNALIGN:
-                        error = GET_UNALIGN_CTL(current, arg2);
+                        error = GET_UNALIGN_CTL(me, arg2);
                         break;
                 case PR_SET_FPEMU:
-                        error = SET_FPEMU_CTL(current, arg2);
+                        error = SET_FPEMU_CTL(me, arg2);
                         break;
                 case PR_GET_FPEMU:
-                        error = GET_FPEMU_CTL(current, arg2);
+                        error = GET_FPEMU_CTL(me, arg2);
                         break;
                 case PR_SET_FPEXC:
-                        error = SET_FPEXC_CTL(current, arg2);
+                        error = SET_FPEXC_CTL(me, arg2);
                         break;
                 case PR_GET_FPEXC:
-                        error = GET_FPEXC_CTL(current, arg2);
+                        error = GET_FPEXC_CTL(me, arg2);
                         break;
                 case PR_GET_TIMING:
                         error = PR_TIMING_STATISTICAL;
@@ -1675,33 +1757,28 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                 case PR_SET_TIMING:
                         if (arg2 != PR_TIMING_STATISTICAL)
                                 error = -EINVAL;
+                        else
+                                error = 0;
                         break;
 
-                case PR_SET_NAME: {
-                        struct task_struct *me = current;
-                        unsigned char ncomm[sizeof(me->comm)];
-
-                        ncomm[sizeof(me->comm)-1] = 0;
-                        if (strncpy_from_user(ncomm, (char __user *)arg2,
-                                                sizeof(me->comm)-1) < 0)
+                case PR_SET_NAME:
+                        comm[sizeof(me->comm)-1] = 0;
+                        if (strncpy_from_user(comm, (char __user *)arg2,
+                                              sizeof(me->comm) - 1) < 0)
                                 return -EFAULT;
-                        set_task_comm(me, ncomm);
+                        set_task_comm(me, comm);
                         return 0;
-                }
-                case PR_GET_NAME: {
-                        struct task_struct *me = current;
-                        unsigned char tcomm[sizeof(me->comm)];
-
-                        get_task_comm(tcomm, me);
-                        if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
+                case PR_GET_NAME:
+                        get_task_comm(comm, me);
+                        if (copy_to_user((char __user *)arg2, comm,
+                                         sizeof(comm)))
                                 return -EFAULT;
                         return 0;
-                }
                 case PR_GET_ENDIAN:
-                        error = GET_ENDIAN(current, arg2);
+                        error = GET_ENDIAN(me, arg2);
                         break;
                 case PR_SET_ENDIAN:
-                        error = SET_ENDIAN(current, arg2);
+                        error = SET_ENDIAN(me, arg2);
                         break;
 
                 case PR_GET_SECCOMP:
@@ -1725,6 +1802,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                                         current->default_timer_slack_ns;
                         else
                                 current->timer_slack_ns = arg2;
+                        error = 0;
                         break;
                 default:
                         error = -EINVAL;