Commit 935d1e45 authored Oct 25, 2019 by Pavel Begunkov Committed by Jens Axboe Oct 25, 2019

io_uring: Fix race for sqes with userspace



io_ring_submit() finalises with
1. io_commit_sqring(), which releases sqes to the userspace
2. Then calls to io_queue_link_head(), accessing released head's sqe

Reorder them.

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

parent fb5ccc98

fs/io_uring.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2795,13 +2795,14 @@ out:
		submit++;
		io_submit_sqe(ctx, &s, statep, &link);
		}
		io_commit_sqring(ctx);

		if (link)
		io_queue_link_head(ctx, link, &link->submit, shadow_req);
		if (statep)
		io_submit_state_end(statep);

		io_commit_sqring(ctx);

		return submit;
		}

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