Commit d5e16d8e authored Jul 24, 2020 by Pavel Begunkov Committed by Jens Axboe Jul 24, 2020

io_uring: fix ->work corruption with poll_add



req->work might be already initialised by the time it gets into
__io_arm_poll_handler(), which will corrupt it by using fields that are
in an union with req->work. Luckily, the only side effect is missing
put_creds(). Clean req->work before going there.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 3e863ea3

fs/io_uring.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -4658,6 +4658,10 @@ static int io_poll_add(struct io_kiocb *req)
		struct io_poll_table ipt;
		__poll_t mask;

		/* ->work is in union with hash_node and others */
		io_req_work_drop_env(req);
		req->flags &= ~REQ_F_WORK_INITIALIZED;

		INIT_HLIST_NODE(&req->hash_node);
		INIT_LIST_HEAD(&req->list);
		ipt.pt._qproc = io_poll_queue_proc;

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