https://github.com/torvalds/linux
Revision 678ff6a7afccc43d352c1b8c94b6d8c0ee1464ad authored by Shakeel Butt on 26 September 2020, 14:13:41 UTC, committed by Linus Torvalds on 26 September 2020, 17:15:01 UTC
With the commit 10befea91b61 ("mm: memcg/slab: use a single set of
kmem_caches for all allocations"), it becomes possible to call kfree()
from the slabs_destroy().

The functions cache_flusharray() and do_drain() calls slabs_destroy() on
array_cache of the local CPU without updating the size of the
array_cache.  This enables the kfree() call from the slabs_destroy() to
recursively call cache_flusharray() which can potentially call
free_block() on the same elements of the array_cache of the local CPU
and causing double free and memory corruption.

To fix the issue, simply update the local CPU array_cache cache before
calling slabs_destroy().

Fixes: 10befea91b61 ("mm: memcg/slab: use a single set of kmem_caches for all allocations")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ted Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 7c7ec32
History
Tip revision: 678ff6a7afccc43d352c1b8c94b6d8c0ee1464ad authored by Shakeel Butt on 26 September 2020, 14:13:41 UTC
mm: slab: fix potential double free in ___cache_free
Tip revision: 678ff6a
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