Commit a4d416dc authored by linke li's avatar linke li Committed by Jens Axboe
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io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it 



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: default avatarlinke li <lilinke99@qq.com>
Link: https://lore.kernel.org/r/tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 039a2e80

io_uring/msg_ring.c

+1 −1
Original line number Diff line number Diff line
@@ -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;