The patch below does not apply to the 5.4-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-5.4.y git checkout FETCH_HEAD git cherry-pick -x 3d8f874bd620ce03f75a5512847586828ab86544 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024052549-gyration-replica-129f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 3d8f874bd620ce03f75a5512847586828ab86544 Mon Sep 17 00:00:00 2001 From: Ming Lei ming.lei@redhat.com Date: Fri, 10 May 2024 11:50:27 +0800 Subject: [PATCH] io_uring: fail NOP if non-zero op flags is passed in

The NOP op flags should have been checked from beginning like any other opcode, otherwise NOP may not be extended with the op flags.

Given both liburing and Rust io-uring crate always zeros SQE op flags, just ignore users which play raw NOP uring interface without zeroing SQE, because NOP is just for test purpose. Then we can save one NOP2 opcode.

Suggested-by: Jens Axboe axboe@kernel.dk Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk

diff --git a/io_uring/nop.c b/io_uring/nop.c index d956599a3c1b..1a4e312dfe51 100644 --- a/io_uring/nop.c +++ b/io_uring/nop.c @@ -12,6 +12,8 @@

int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + if (READ_ONCE(sqe->rw_flags)) + return -EINVAL; return 0; }