io_uring/net: don't clear REQ_F_NEED_CLEANUP unconditionally

io_req_msg_cleanup() relies on the fact that io_netmsg_recycle() will
always fully recycle, but that may not be the case if the msg cache
was already full. To ensure that normal cleanup always gets run,
let io_netmsg_recycle() deal with clearing the relevant cleanup flags,
as it knows exactly when that should be done.

Cc: stable@vger.kernel.org
Reported-by: David Wei <dw@davidwei.uk>
Fixes: 7519134 ("io_uring/net: add iovec recycling")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: axboe

io_uring/net.c

@@ -148,7 +148,7 @@ static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
 	io_alloc_cache_kasan(&hdr->free_iov, &hdr->free_iov_nr);
 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr)) {
 		req->async_data = NULL;
-		req->flags &= ~REQ_F_ASYNC_DATA;
+		req->flags &= ~(REQ_F_ASYNC_DATA|REQ_F_NEED_CLEANUP);
 	}
 }
 
@@ -441,7 +441,6 @@ int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 static void io_req_msg_cleanup(struct io_kiocb *req,
 			       unsigned int issue_flags)
 {
-	req->flags &= ~REQ_F_NEED_CLEANUP;
 	io_netmsg_recycle(req, issue_flags);
 }