io_uring: retain sockaddr_storage across send/recvmsg async punt

mainline inclusion
from mainline-5.6-rc2
commit b537916c
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

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>
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/io_uring.c

@@ -443,6 +443,7 @@ struct io_async_msghdr {
 	struct iovec			*iov;
 	struct sockaddr __user		*uaddr;
 	struct msghdr			msg;
+	struct sockaddr_storage		addr;
 };
 
 struct io_async_rw {
@@ -2978,12 +2979,11 @@ 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;
@@ -2992,7 +2992,7 @@ 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,
@@ -3131,12 +3131,11 @@ 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;
@@ -3145,7 +3144,7 @@ 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,