From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: [PATCH] brd: Refuse improperly aligned discard requests Date: Wed, 4 Nov 2015 17:13:39 +0100 Message-ID: <1446653619-22880-1-git-send-email-jack@suse.com> Cc: LKML , linux-fsdevel@vger.kernel.org, Christoph Hellwig , Jan Kara To: axboe@kernel.dk Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Currently when improperly aligned discard request is submitted, we just silently discard more / less data which results in filesystem corruption in some cases. Refuse such misaligned requests. Signed-off-by: Jan Kara --- drivers/block/brd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index b9794aeeb878..4ef4cdf67ede 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -337,6 +337,9 @@ static void brd_make_request(struct request_queue *q, struct bio *bio) goto io_error; if (unlikely(bio->bi_rw & REQ_DISCARD)) { + if (sector & ((PAGE_SIZE >> SECTOR_SHIFT) - 1) || + bio->bi_iter.bi_size & PAGE_MASK) + goto io_error; discard_from_brd(brd, sector, bio->bi_iter.bi_size); goto out; } -- 2.1.4