io_uring/net: don't overflow multishot recv

Don't allow overflowing multishot recv CQEs, it might get out of
hand, hurt performance, and in the worst case scenario OOM the task.

Cc: stable@vger.kernel.org
Fixes: b3fdea6ecb55c ("io_uring: multishot recv")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/0b295634e8f1b71aa764c984608c22d85f88f75c.1691757663.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 1599493544a55ec72c2f4b27a9678761a18a34d3..8c419c01a5dba751873aaf01d471b23d51f02899 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -642,7 +642,7 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
 
        if (!mshot_finished) {
                if (io_aux_cqe(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
-                              *ret, cflags | IORING_CQE_F_MORE, true)) {
+                              *ret, cflags | IORING_CQE_F_MORE, false)) {
                        io_recv_prep_retry(req);
                        /* Known not-empty or unknown state, retry */
                        if (cflags & IORING_CQE_F_SOCK_NONEMPTY ||