This is a note to let you know that I've just added the patch titled io_uring: ensure symmetry in handling iter types in loop_rw_iter() to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-ensure-symmetry-in-handling-iter-types-in-loop_rw_iter.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe@xxxxxxxxx> Date: Sun, 12 Sep 2021 06:45:07 -0600 Subject: io_uring: ensure symmetry in handling iter types in loop_rw_iter() From: Jens Axboe <axboe@xxxxxxxxx> commit 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc upstream. When setting up the next segment, we check what type the iter is and handle it accordingly. However, when incrementing and processed amount we do not, and both iter advance and addr/len are adjusted, regardless of type. Split the increment side just like we do on the setup side. Fixes: 4017eb91a9e7 ("io_uring: make loop_rw_iter() use original user supplied pointers") Cc: stable@xxxxxxxxxxxxxxx Reported-by: Valentina Palmiotti <vpalmiotti@xxxxxxxxx> Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3107,12 +3107,15 @@ static ssize_t loop_rw_iter(int rw, stru ret = nr; break; } + if (!iov_iter_is_bvec(iter)) { + iov_iter_advance(iter, nr); + } else { + req->rw.len -= nr; + req->rw.addr += nr; + } ret += nr; if (nr != iovec.iov_len) break; - req->rw.len -= nr; - req->rw.addr += nr; - iov_iter_advance(iter, nr); } return ret; Patches currently in stable-queue which might be from axboe@xxxxxxxxx are queue-5.14/io_uring-ensure-symmetry-in-handling-iter-types-in-loop_rw_iter.patch