io_uring: retain sockaddr_storage across send/recvmsg async punt

Jonas reports that he sometimes sees -97/-22 error returns from
sendmsg, if it gets punted async. This is due to not retaining the
sockaddr_storage between calls. Include that in the state we copy when
going async.

Cc: stable@vger.kernel.org # 5.3+
Reported-by: NJonas Bonn <jonas@norrbonn.se>
Tested-by: NJonas Bonn <jonas@norrbonn.se>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -442,6 +442,7 @@ struct io_async_msghdr {
 	struct iovec			*iov;
 	struct sockaddr __user		*uaddr;
 	struct msghdr			msg;
+	struct sockaddr_storage		addr;
 };
 
 struct io_async_rw {
@@ -3032,12 +3033,11 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_async_ctx io;
-		struct sockaddr_storage addr;
 		unsigned flags;
 
 		if (req->io) {
 			kmsg = &req->io->msg;
-			kmsg->msg.msg_name = &addr;
+			kmsg->msg.msg_name = &req->io->msg.addr;
 			/* if iov is set, it's allocated already */
 			if (!kmsg->iov)
 				kmsg->iov = kmsg->fast_iov;
@@ -3046,7 +3046,7 @@ static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			struct io_sr_msg *sr = &req->sr_msg;
 
 			kmsg = &io.msg;
-			kmsg->msg.msg_name = &addr;
+			kmsg->msg.msg_name = &io.msg.addr;
 
 			io.msg.iov = io.msg.fast_iov;
 			ret = sendmsg_copy_msghdr(&io.msg.msg, sr->msg,
@@ -3185,12 +3185,11 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 	sock = sock_from_file(req->file, &ret);
 	if (sock) {
 		struct io_async_ctx io;
-		struct sockaddr_storage addr;
 		unsigned flags;
 
 		if (req->io) {
 			kmsg = &req->io->msg;
-			kmsg->msg.msg_name = &addr;
+			kmsg->msg.msg_name = &req->io->msg.addr;
 			/* if iov is set, it's allocated already */
 			if (!kmsg->iov)
 				kmsg->iov = kmsg->fast_iov;
@@ -3199,7 +3198,7 @@ static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt,
 			struct io_sr_msg *sr = &req->sr_msg;
 
 			kmsg = &io.msg;
-			kmsg->msg.msg_name = &addr;
+			kmsg->msg.msg_name = &io.msg.addr;
 
 			io.msg.iov = io.msg.fast_iov;
 			ret = recvmsg_copy_msghdr(&io.msg.msg, sr->msg,