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| author | Felipe Pena <felipensp@gmail.com> | 2013-11-09 19:36:09 +0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-11-26 20:24:01 +0400 |
| commit | 2f089cb89d2f47702c31bd584c12badc88bbe17c (patch) | |
| tree | 3041158a5ba7d03f4f4f93197c86095794a585b6 /drivers/block/xen-blkfront.c | |
| parent | 427bfe07e6744c058ce6fc4aa187cda96b635539 (diff) | |
| download | linux-2f089cb89d2f47702c31bd584c12badc88bbe17c.tar.xz | |
block: xen-blkfront: Fix possible NULL ptr dereference
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>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added WARN per Roger's suggestion]
Diffstat (limited to 'drivers/block/xen-blkfront.c')
| -rw-r--r-- | drivers/block/xen-blkfront.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 5f926de61950..c4a4c9006288 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -2011,6 +2011,10 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) bdev = bdget_disk(disk, 0); + if (!bdev) { + WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); + goto out_mutex; + } if (bdev->bd_openers) goto out; @@ -2041,6 +2045,7 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) out: bdput(bdev); +out_mutex: mutex_unlock(&blkfront_mutex); } |