Merge tag 'v3.10.59' into update

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / user_namespace.c

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index d8c30db06c5b75456098fe2f1a26785e9a9110ee..9bea1d7dd21fac61c2084cb5bc295c1980c2573e 100644 (file)
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -62,6 +62,9 @@ int create_user_ns(struct cred *new)
        kgid_t group = new->egid;
        int ret;
 
+       if (parent_ns->level > 32)
+               return -EUSERS;
+
        /*
         * Verify that we can not violate the policy of which files
         * may be accessed that is specified by the root directory,
@@ -92,6 +95,7 @@ int create_user_ns(struct cred *new)
        atomic_set(&ns->count, 1);
        /* Leave the new->user_ns reference with the new user namespace. */
        ns->parent = parent_ns;
+       ns->level = parent_ns->level + 1;
        ns->owner = owner;
        ns->group = group;
 
@@ -105,16 +109,21 @@ int create_user_ns(struct cred *new)
 int unshare_userns(unsigned long unshare_flags, struct cred **new_cred)
 {
        struct cred *cred;
+       int err = -ENOMEM;
 
        if (!(unshare_flags & CLONE_NEWUSER))
                return 0;
 
        cred = prepare_creds();
-       if (!cred)
-               return -ENOMEM;
+       if (cred) {
+               err = create_user_ns(cred);
+               if (err)
+                       put_cred(cred);
+               else
+                       *new_cred = cred;
+       }
 
-       *new_cred = cred;
-       return create_user_ns(cred);
+       return err;
 }
 
 void free_user_ns(struct user_namespace *ns)
@@ -139,7 +148,7 @@ static u32 map_id_range_down(struct uid_gid_map *map, u32 id, u32 count)
 
        /* Find the matching extent */
        extents = map->nr_extents;
-       smp_read_barrier_depends();
+       smp_rmb();
        for (idx = 0; idx < extents; idx++) {
                first = map->extent[idx].first;
                last = first + map->extent[idx].count - 1;
@@ -163,7 +172,7 @@ static u32 map_id_down(struct uid_gid_map *map, u32 id)
 
        /* Find the matching extent */
        extents = map->nr_extents;
-       smp_read_barrier_depends();
+       smp_rmb();
        for (idx = 0; idx < extents; idx++) {
                first = map->extent[idx].first;
                last = first + map->extent[idx].count - 1;
@@ -186,7 +195,7 @@ static u32 map_id_up(struct uid_gid_map *map, u32 id)
 
        /* Find the matching extent */
        extents = map->nr_extents;
-       smp_read_barrier_depends();
+       smp_rmb();
        for (idx = 0; idx < extents; idx++) {
                first = map->extent[idx].lower_first;
                last = first + map->extent[idx].count - 1;
@@ -602,9 +611,8 @@ static ssize_t map_write(struct file *file, const char __user *buf,
         * were written before the count of the extents.
         *
         * To achieve this smp_wmb() is used on guarantee the write
-        * order and smp_read_barrier_depends() is guaranteed that we
-        * don't have crazy architectures returning stale data.
-        *
+        * order and smp_rmb() is guaranteed that we don't have crazy
+        * architectures returning stale data.
         */
        mutex_lock(&id_map_mutex);