Commit d5e7b3c5 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

userns: Don't read extents twice in m_start 



This is important so reading /proc/<pid>/{uid_map,gid_map,projid_map} while
the map is being written does not do strange things.

Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 3edf652f

kernel/user_namespace.c

+4 −2
Original line number Diff line number Diff line
@@ -683,11 +683,13 @@ static void *m_start(struct seq_file *seq, loff_t *ppos, 
		     struct uid_gid_map *map)

{

	loff_t pos = *ppos;

	unsigned extents = map->nr_extents;

	smp_rmb();



	if (pos >= map->nr_extents)

	if (pos >= extents)

		return NULL;



	if (map->nr_extents <= UID_GID_MAP_MAX_BASE_EXTENTS)

	if (extents <= UID_GID_MAP_MAX_BASE_EXTENTS)

		return &map->extent[pos];



	return &map->forward[pos];