2012-08-09 05:53:27

by Alexey Khoroshilov

Subject: [PATCH] bio: Fix potential memory leak in bio_find_or_create_slab()

Do not leak memory by updating pointer with potentially NULL realloc return value.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
fs/bio.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/bio.c b/fs/bio.c
index 5eaa70c..3fb4380 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -73,7 +73,7 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
{
unsigned int sz = sizeof(struct bio) + extra_size;
struct kmem_cache *slab = NULL;
- struct bio_slab *bslab;
+ struct bio_slab *bslab, *new_bio_slabs;
unsigned int i, entry = -1;

mutex_lock(&bio_slab_lock);
@@ -97,11 +97,12 @@ static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)

if (bio_slab_nr == bio_slab_max && entry == -1) {
bio_slab_max <<= 1;
- bio_slabs = krealloc(bio_slabs,
- bio_slab_max * sizeof(struct bio_slab),
- GFP_KERNEL);
- if (!bio_slabs)
+ new_bio_slabs = krealloc(bio_slabs,
+ bio_slab_max * sizeof(struct bio_slab),
+ GFP_KERNEL);
+ if (!new_bio_slabs)
goto out_unlock;
+ bio_slabs = new_bio_slabs;
}
if (entry == -1)
entry = bio_slab_nr++;
--
1.7.9.5

2012-08-09 13:16:13

by Jeff Moyer

Subject: Re: [PATCH] bio: Fix potential memory leak in bio_find_or_create_slab()

Alexey Khoroshilov <[email protected]> writes:

> Do not leak memory by updating pointer with potentially NULL realloc return value.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>

Acked-by: Jeff Moyer <[email protected]>

2012-08-09 13:20:00

by Jens Axboe

Subject: Re: [PATCH] bio: Fix potential memory leak in bio_find_or_create_slab()

On 08/09/2012 07:52 AM, Alexey Khoroshilov wrote:
> Do not leak memory by updating pointer with potentially NULL realloc return value.
>
> Found by Linux Driver Verification project (linuxtesting.org).

Thanks, applied.

--
Jens Axboe