diff options
| author | Sean Rees <sean@erifax.org> | 2017-02-08 14:30:59 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-14 15:25:35 -0800 |
| commit | 49f68ccccf8e502bce967126207211f5a27feb4c (patch) | |
| tree | 5f7b407c45f828b1ca02f50a95e4f0e6735b180f /mm | |
| parent | c4236b0c71169b6e5fb5f2272dd0292156c81e97 (diff) | |
mm/slub.c: fix random_seq offset destruction
commit a810007afe239d59c1115fcaa06eb5b480f876e9 upstream.
Commit 210e7a43fa90 ("mm: SLUB freelist randomization") broke USB hub
initialisation as described in
https://bugzilla.kernel.org/show_bug.cgi?id=177551.
Bail out early from init_cache_random_seq if s->random_seq is already
initialised. This prevents destroying the previously computed
random_seq offsets later in the function.
If the offsets are destroyed, then shuffle_freelist will truncate
page->freelist to just the first object (orphaning the rest).
Fixes: 210e7a43fa90 ("mm: SLUB freelist randomization")
Link: http://lkml.kernel.org/r/20170207140707.20824-1-sean@erifax.org
Signed-off-by: Sean Rees <sean@erifax.org>
Reported-by: <userwithuid@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/slub.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/slub.c b/mm/slub.c index 2b3e740609e9..7aa0e97af928 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1419,6 +1419,10 @@ static int init_cache_random_seq(struct kmem_cache *s) int err; unsigned long i, count = oo_objects(s->oo); + /* Bailout if already initialised */ + if (s->random_seq) + return 0; + err = cache_random_seq_create(s, count, GFP_KERNEL); if (err) { pr_err("SLUB: Unable to initialize free list for %s\n", |