From 1a43ac1ef948149973ebcc4859b99fa94665bc18 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 12 Sep 2021 06:45:07 -0600 Subject: [PATCH] io_uring: ensure symmetry in handling iter types in loop_rw_iter() [upstream commit 16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc] 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@vger.kernel.org Reported-by: Valentina Palmiotti Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0138aa7133172..4e1f43b4406d2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3203,12 +3203,15 @@ static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) 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;