diff mbox series

[3/3] io_uring: Fix race for sqes with userspace

Message ID cfb7206ba1ac48615fd705ac74fc2d554a0c5422.1571991701.git.asml.silence@gmail.com (mailing list archive)
State New, archived
Headers show
Series Fix bunch of bugs in io_uring | expand

Commit Message

Pavel Begunkov Oct. 25, 2019, 9:31 a.m. UTC 
From: Pavel Begunkov <asml.silence@gmail.com>

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>
---
 fs/io_uring.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 949c82a40d16..32f6598ecae9 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2795,13 +2795,14 @@  static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit)
 		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;
 }