[PATCH for-next 1/2] io_uring/net: don't update msg_name if not provided

[Pavel Begunkov <asml.silence@gmail.com>]

io_sendmsg_copy_hdr() may clear msg->msg_name if the userspace didn't
provide it, we should retain NULL in this case.

Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 9ada9da02d04..604eac5f7a34 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -164,7 +164,8 @@ static int io_setup_async_msg(struct io_kiocb *req,
 	}
 	req->flags |= REQ_F_NEED_CLEANUP;
 	memcpy(async_msg, kmsg, sizeof(*kmsg));
-	async_msg->msg.msg_name = &async_msg->addr;
+	if (async_msg->msg.msg_name)
+		async_msg->msg.msg_name = &async_msg->addr;
 	/* if were using fast_iov, set it to the new one */
 	if (!kmsg->free_iov) {
 		size_t fast_idx = kmsg->msg.msg_iter.iov - kmsg->fast_iov;
-- 
2.37.2