From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sat, 20 Feb 2021 01:39:53 +0000 (+0000)
Subject: io_uring: fix leaving invalid req->flags
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ebf4a5db690a47e71056381ead8a134de7202694;p=linux.git

io_uring: fix leaving invalid req->flags

sqe->flags are subset of req flags, so incorrectly copied may span into
in-kernel flags and wreck havoc, e.g. by setting REQ_F_INFLIGHT.

Fixes: 5be9ad1e4287e ("io_uring: optimise io_init_req() flags setting")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5cc02226bb38e..1501f20fde844 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6679,8 +6679,10 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 	req->result = 0;
 
 	/* enforce forwards compatibility on users */
-	if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
+	if (unlikely(sqe_flags & ~SQE_VALID_FLAGS)) {
+		req->flags = 0;
 		return -EINVAL;
+	}
 
 	if (unlikely(req->opcode >= IORING_OP_LAST))
 		return -EINVAL;