The patch below does not apply to the 6.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.4.y git checkout FETCH_HEAD git cherry-pick -x b2e74db55dd93d6db22a813c9a775b5dbf87c560 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023090908-cursor-reshape-7963@gregkh' --subject-prefix 'PATCH 6.4.y' HEAD^..

Possible dependencies:

b2e74db55dd9 ("io_uring/net: don't overflow multishot recv") d86eaed185e9 ("io_uring: cleanup io_aux_cqe() API")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b2e74db55dd93d6db22a813c9a775b5dbf87c560 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov asml.silence@gmail.com Date: Fri, 11 Aug 2023 13:53:42 +0100 Subject: [PATCH] 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.169175766... Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/io_uring/net.c b/io_uring/net.c index 1599493544a5..8c419c01a5db 100644 --- 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 ||