mm, slab: initialize object alignment on cache creation
Since commit 4590685546
("mm/sl[aou]b: Common alignment code"), the
"ralign" automatic variable in __kmem_cache_create() may be used as
uninitialized.
The proper alignment defaults to BYTES_PER_WORD and can be overridden by
SLAB_RED_ZONE or the alignment specified by the caller.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=85031
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Andrei Elovikov <a.elovikov@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
87e6d49a00
commit
d4a5fca592
11
mm/slab.c
11
mm/slab.c
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@ -2124,7 +2124,8 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
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int
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__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
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{
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size_t left_over, freelist_size, ralign;
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size_t left_over, freelist_size;
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size_t ralign = BYTES_PER_WORD;
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gfp_t gfp;
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int err;
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size_t size = cachep->size;
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@ -2157,14 +2158,6 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
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size &= ~(BYTES_PER_WORD - 1);
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}
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/*
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* Redzoning and user store require word alignment or possibly larger.
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* Note this will be overridden by architecture or caller mandated
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* alignment if either is greater than BYTES_PER_WORD.
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*/
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if (flags & SLAB_STORE_USER)
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ralign = BYTES_PER_WORD;
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if (flags & SLAB_RED_ZONE) {
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ralign = REDZONE_ALIGN;
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/* If redzoning, ensure that the second redzone is suitably
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