FAILED: patch "[PATCH] io_uring: prevent opcode speculation" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 1e988c3fe1264708f4f92109203ac5b1d65de50b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025022440-shadow-ambitious-5060@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 1e988c3fe1264708f4f92109203ac5b1d65de50b Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Fri, 14 Feb 2025 22:48:15 +0000
Subject: [PATCH] io_uring: prevent opcode speculation

sqe->opcode is used for different tables, make sure we santitise it
against speculations.

Cc: stable@vger.kernel.org
Fixes: d3656344fea03 ("io_uring: add lookup table for various opcode needs")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Li Zetao <lizetao1@huawei.com>
Link: https://lore.kernel.org/r/7eddbf31c8ca0a3947f8ed98271acc2b4349c016.1739568408.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 263e504be4a8..29a42365a481 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2045,6 +2045,8 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 		req->opcode = 0;
 		return io_init_fail_req(req, -EINVAL);
 	}
+	opcode = array_index_nospec(opcode, IORING_OP_LAST);
+
 	def = &io_issue_defs[opcode];
 	if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) {
 		/* enforce forwards compatibility on users */