From 2dbe5495763612f7c1b68fc897cd28c9e22079b8 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 4 Nov 2015 17:13:39 +0100 Subject: [PATCH] brd: Refuse improperly aligned discard requests 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 Signed-off-by: Jens Axboe --- drivers/block/brd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/brd.c b/drivers/block/brd.c index c9f9c30d6467..a5880f4ab40e 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -337,6 +337,9 @@ static blk_qc_t 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; } -- 2.39.2