Commit d6fef34e authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

io_uring: fix off-by one bvec index 



If the offset equals the bv_len of the first registered bvec, then the
request does not include any of that first bvec. Skip it so that drivers
don't have to deal with a zero length bvec, which was observed to break
NVMe's PRP list creation.

Cc: stable@vger.kernel.org
Fixes: bd11b3a3 ("io_uring: don't use iov_iter_advance() for fixed buffers")
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20231120221831.2646460-1-kbusch@meta.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8479063f

io_uring/rsrc.c

+1 −1
Original line number Diff line number Diff line
@@ -1258,7 +1258,7 @@ int io_import_fixed(int ddir, struct iov_iter *iter, 
		 */

		const struct bio_vec *bvec = imu->bvec;



		if (offset <= bvec->bv_len) {

		if (offset < bvec->bv_len) {

			/*

			 * Note, huge pages buffers consists of one large

			 * bvec entry and should always go this way. The other