1 files changed, 245 insertions, 205 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index ccc9eb736d35..ab735040468a 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -180,7 +180,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        user = cred->user;
+                        user = (struct user_struct *) cred->user;
                         if (!who)
                                 who = cred->uid;
                         else if ((who != cred->uid) &&
@@ -479,47 +479,48 @@ void ctrl_alt_del(void)
  */
 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 {
-        struct cred *cred = current->cred;
-        int old_rgid = cred->gid;
-        int old_egid = cred->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) ||
-                    (cred->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) ||
-                    (cred->egid == egid) ||
-                    (cred->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))
-                cred->sgid = new_egid;
-        cred->fsgid = new_egid;
-        cred->egid = new_egid;
-        cred->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;
 }
 
 /*
@@ -529,40 +530,42 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
  */
 asmlinkage long sys_setgid(gid_t gid)
 {
-        struct cred *cred = current->cred;
-        int old_egid = cred->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();
-                }
-                cred->gid = cred->egid = cred->sgid = cred->fsgid = gid;
-        } else if ((gid == cred->gid) || (gid == cred->sgid)) {
-                if (old_egid != gid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                cred->egid = cred->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->nsproxy->user_ns, new->uid);
         if (!new_user)
                 return -EAGAIN;
 
@@ -573,13 +576,8 @@ static int set_user(uid_t new_ruid, int dumpclear)
                 return -EAGAIN;
         }
 
-        switch_uid(new_user);
-
-        if (dumpclear) {
-                set_dumpable(current->mm, suid_dumpable);
-                smp_wmb();
-        }
-        current->cred->uid = new_ruid;
+        free_uid(new->user);
+        new->user = new_user;
         return 0;
 }
 
@@ -600,55 +598,56 @@ static int set_user(uid_t new_ruid, int dumpclear)
  */
 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 {
-        struct cred *cred = current->cred;
-        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 = cred->uid;
-        new_euid = old_euid = cred->euid;
-        old_suid = cred->suid;
+                goto error;
 
+        retval = -EPERM;
         if (ruid != (uid_t) -1) {
-                new_ruid = ruid;
-                if ((old_ruid != ruid) &&
-                    (cred->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) &&
-                    (cred->euid != euid) &&
-                    (cred->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();
-        }
-        cred->fsuid = cred->euid = new_euid;
         if (ruid != (uid_t) -1 ||
-            (euid != (uid_t) -1 && euid != old_ruid))
-                cred->suid = cred->euid;
-        cred->fsuid = cred->euid;
-
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
+            (euid != (uid_t) -1 && euid != old->uid))
+                new->suid = new->euid;
+        new->fsuid = new->euid;
 
-        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 
@@ -663,37 +662,41 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
  */
 asmlinkage long sys_setuid(uid_t uid)
 {
-        struct cred *cred = current->cred;
-        int old_euid = cred->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 = cred->uid;
-        old_suid = cred->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 != cred->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;
         }
-        cred->fsuid = cred->euid = uid;
-        cred->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 commit_creds(new);
 
-        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
+error:
+        abort_creds(new);
+        return retval;
 }
 
 
@@ -703,47 +706,53 @@ asmlinkage long sys_setuid(uid_t uid)
  */
 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-        struct cred *cred = current->cred;
-        int old_ruid = cred->uid;
-        int old_euid = cred->euid;
-        int old_suid = cred->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 != cred->uid) &&
-                    (ruid != cred->euid) && (ruid != cred->suid))
-                        return -EPERM;
-                if ((euid != (uid_t) -1) && (euid != cred->uid) &&
-                    (euid != cred->euid) && (euid != cred->suid))
-                        return -EPERM;
-                if ((suid != (uid_t) -1) && (suid != cred->uid) &&
-                    (suid != cred->euid) && (suid != cred->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 != cred->uid &&
-                    set_user(ruid, euid != cred->euid) < 0)
-                        return -EAGAIN;
+                new->uid = ruid;
+                if (ruid != old->uid && set_user(new) < 0)
+                        goto error;
         }
-        if (euid != (uid_t) -1) {
-                if (euid != cred->euid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                cred->euid = euid;
-        }
-        cred->fsuid = cred->euid;
+        if (euid != (uid_t) -1)
+                new->euid = euid;
         if (suid != (uid_t) -1)
-                cred->suid = suid;
+                new->suid = suid;
+        new->fsuid = new->euid;
 
-        key_fsuid_changed(current);
-        proc_id_connector(current, PROC_EVENT_UID);
+        retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
+        if (retval < 0)
+                goto error;
 
-        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
+        return commit_creds(new);
+
+error:
+        abort_creds(new);
+        return retval;
 }
 
 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
@@ -763,40 +772,45 @@ 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)
 {
-        struct cred *cred = current->cred;
+        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 != cred->gid) &&
-                    (rgid != cred->egid) && (rgid != cred->sgid))
-                        return -EPERM;
-                if ((egid != (gid_t) -1) && (egid != cred->gid) &&
-                    (egid != cred->egid) && (egid != cred->sgid))
-                        return -EPERM;
-                if ((sgid != (gid_t) -1) && (sgid != cred->gid) &&
-                    (sgid != cred->egid) && (sgid != cred->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 != cred->egid) {
-                        set_dumpable(current->mm, suid_dumpable);
-                        smp_wmb();
-                }
-                cred->egid = egid;
-        }
-        cred->fsgid = cred->egid;
+
         if (rgid != (gid_t) -1)
-                cred->gid = rgid;
+                new->gid = rgid;
+        if (egid != (gid_t) -1)
+                new->egid = egid;
         if (sgid != (gid_t) -1)
-                cred->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)
@@ -820,28 +834,35 @@ asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __us
  */
 asmlinkage long sys_setfsuid(uid_t uid)
 {
-        struct cred *cred = current->cred;
-        int old_fsuid;
+        const struct cred *old;
+        struct cred *new;
+        uid_t old_fsuid;
+
+        new = prepare_creds();
+        if (!new)
+                return current_fsuid();
+        old = current_cred();
+        old_fsuid = old->fsuid;
 
-        old_fsuid = cred->fsuid;
-        if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
-                return old_fsuid;
+        if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
+                goto error;
 
-        if (uid == cred->uid || uid == cred->euid ||
-            uid == cred->suid || uid == cred->fsuid ||
+        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;
                 }
-                cred->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;
 }
 
@@ -850,24 +871,34 @@ asmlinkage long sys_setfsuid(uid_t uid)
  */
 asmlinkage long sys_setfsgid(gid_t gid)
 {
-        struct cred *cred = current->cred;
-        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 = cred->fsgid;
         if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
-                return old_fsgid;
+                goto error;
 
-        if (gid == cred->gid || gid == cred->egid ||
-            gid == cred->sgid || gid == cred->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;
                 }
-                cred->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;
 }
 
@@ -1136,7 +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;
@@ -1227,31 +1258,25 @@ int groups_search(const struct group_info *group_info, gid_t grp)
 }
 
 /**
- * set_groups - Change a group subscription in a security record
- * @sec: The security record to alter
- * @group_info: The group list to impose
+ * 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, impose it upon a task security
- * record.
+ * Validate a group subscription and, if valid, insert it into a set
+ * of credentials.
  */
-int set_groups(struct cred *cred, struct group_info *group_info)
+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);
-
-        spin_lock(&cred->lock);
-        old_info = cred->group_info;
-        cred->group_info = group_info;
-        spin_unlock(&cred->lock);
-
-        put_group_info(old_info);
+        new->group_info = group_info;
         return 0;
 }
 
@@ -1266,7 +1291,20 @@ EXPORT_SYMBOL(set_groups);
  */
 int set_current_groups(struct group_info *group_info)
 {
-        return set_groups(current->cred, group_info);
+        struct cred *new;
+        int ret;
+
+        new = prepare_creds();
+        if (!new)
+                return -ENOMEM;
+
+        ret = set_groups(new, group_info);
+        if (ret < 0) {
+                abort_creds(new);
+                return ret;
+        }
+
+        return commit_creds(new);
 }
 
 EXPORT_SYMBOL(set_current_groups);
@@ -1666,9 +1704,11 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
         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)) {