[PATCH 6.0 016/862] io_uring/net: dont update msg_name if not provided

[Greg Kroah-Hartman]

From: Pavel Begunkov <asml.silence@xxxxxxxxx>

commit 6f10ae8a155446248055c7ddd480ef40139af788 upstream.

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@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/97d49f61b5ec76d0900df658cfde3aa59ff22121.1664486545.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 io_uring/net.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -163,7 +163,8 @@ static int io_setup_async_msg(struct io_
 	}
 	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;