Messages in this thread Patch in this message | | | From | Felipe Pena <> | Subject | [PATCH] block: xen-blkfront: Fix possible NULL ptr dereference | Date | Sat, 9 Nov 2013 13:36:09 -0200 |
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In the blkif_release function the bdget_disk() call might returns a NULL ptr which might be dereferenced on bdev->bd_openers checking
Signed-off-by: Felipe Pena <felipensp@gmail.com> --- drivers/block/xen-blkfront.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index a4660bb..7bb1552 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -1959,6 +1959,9 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) bdev = bdget_disk(disk, 0); + if (!bdev) + goto out_mutex; + if (bdev->bd_openers) goto out; @@ -1989,6 +1992,7 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) out: bdput(bdev); +out_mutex: mutex_unlock(&blkfront_mutex); } -- 1.7.10.4
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