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| author | Sean Rees <sean@erifax.org> | 2017-02-08 14:30:59 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-08 15:41:43 -0800 |
| commit | a810007afe239d59c1115fcaa06eb5b480f876e9 (patch) | |
| tree | 25bbc5efa479af7cb1ca2defeeffb2040600a2fd /mm/slub.c | |
| parent | 4d59b6ccf000862beed6fc0765d3209f98a8d8a2 (diff) | |
| download | linux-a810007afe239d59c1115fcaa06eb5b480f876e9.tar.gz linux-a810007afe239d59c1115fcaa06eb5b480f876e9.tar.bz2 linux-a810007afe239d59c1115fcaa06eb5b480f876e9.zip | |
mm/slub.c: fix random_seq offset destruction
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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slub.c')
| -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 7aa6f433f4de..7ec0a965c6a3 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1422,6 +1422,10 @@ 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", |