Commit 2f089cb8 authored Nov 09, 2013 by Felipe Pena Committed by Konrad Rzeszutek Wilk Nov 26, 2013

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]

parent 427bfe07

drivers/block/xen-blkfront.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}