From: "Eric W. Biederman" <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit f0d62aec931e4ae3333c797d346dc4f188f454ba upstream. Generalize id_map_mutex so it can be used for more state of a user namespace. Reviewed-by: Andy Lutomirski <[email protected]> Signed-off-by: "Eric W. Biederman" <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- kernel/user_namespace.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index c2ca6c01e575..a607b24bec0b 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -24,6 +24,7 @@ #include <linux/fs_struct.h> static struct kmem_cache *user_ns_cachep __read_mostly; +static DEFINE_MUTEX(userns_state_mutex); static bool new_idmap_permitted(const struct file *file, struct user_namespace *ns, int cap_setid, @@ -575,9 +576,6 @@ static bool mappings_overlap(struct uid_gid_map *new_map, struct uid_gid_extent return false; } - -static DEFINE_MUTEX(id_map_mutex); - static ssize_t map_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos, int cap_setid, @@ -594,7 +592,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, ssize_t ret = -EINVAL; /* - * The id_map_mutex serializes all writes to any given map. + * The userns_state_mutex serializes all writes to any given map. * * Any map is only ever written once. * @@ -612,7 +610,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, * order and smp_rmb() is guaranteed that we don't have crazy * architectures returning stale data. */ - mutex_lock(&id_map_mutex); + mutex_lock(&userns_state_mutex); ret = -EPERM; /* Only allow one successful write to the map */ @@ -739,7 +737,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, *ppos = count; ret = count; out: - mutex_unlock(&id_map_mutex); + mutex_unlock(&userns_state_mutex); if (page) free_page(page); return ret; @@ -831,12 +829,12 @@ bool userns_may_setgroups(const struct user_namespace *ns) { bool allowed; - mutex_lock(&id_map_mutex); + mutex_lock(&userns_state_mutex); /* It is not safe to use setgroups until a gid mapping in * the user namespace has been established. */ allowed = ns->gid_map.nr_extents != 0; - mutex_unlock(&id_map_mutex); + mutex_unlock(&userns_state_mutex); return allowed; } -- 2.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
