Re: FAILED: patch "[PATCH] io_uring: fail NOP if non-zero op flags is passed in" failed to apply to 5.10-stable tree

[Jens Axboe <axboe@kernel.dk>]

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On 5/25/24 9:05 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.10-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-5.10.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 '2024052548-prance-gliding-4f31@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Here's one for 5.10 and 5.15 stable, applies to both.

-- 
Jens Axboe


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From 5f9000aeb13f10df2d00144275d9431ed1118804 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

Commit 3d8f874bd620ce03f75a5512847586828ab86544 upstream.

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>
---
 io_uring/io_uring.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ff6c36aec27c..ea005700c8ce 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -6621,6 +6621,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	switch (req->opcode) {
 	case IORING_OP_NOP:
+		if (READ_ONCE(sqe->rw_flags))
+			return -EINVAL;
 		return 0;
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
-- 
2.43.0