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From: linke li <lilinke99@qq.com>
Cc: xujianhao01@gmail.com, linke li <lilinke99@qq.com>,
	Jens Axboe <axboe@kernel.dk>,
	Pavel Begunkov <asml.silence@gmail.com>,
	io-uring@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
Date: Fri, 26 Apr 2024 11:24:37 +0800	[thread overview]
Message-ID: <tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com> (raw)

In io_msg_exec_remote(), ctx->submitter_task is read using READ_ONCE at
the beginning of the function, checked, and then re-read from
ctx->submitter_task, voiding all guarantees of the checks. Reuse the value
that was read by READ_ONCE to ensure the consistency of the task struct
throughout the function.

Signed-off-by: linke li <lilinke99@qq.com>
---
 io_uring/msg_ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c
index cd6dcf634ba3..d74670b39ed6 100644
--- a/io_uring/msg_ring.c
+++ b/io_uring/msg_ring.c
@@ -83,7 +83,7 @@ static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func)
 		return -EOWNERDEAD;
 
 	init_task_work(&msg->tw, func);
-	if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL))
+	if (task_work_add(task, &msg->tw, TWA_SIGNAL))
 		return -EOWNERDEAD;
 
 	return IOU_ISSUE_SKIP_COMPLETE;
-- 
2.39.3 (Apple Git-146)


             reply	other threads:[~2024-04-26  3:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-26  3:24 linke li [this message]
2024-04-26 13:40 ` [PATCH] io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it Jens Axboe

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