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

From: Greg Kroah-Hartman
Date: Wed Oct 19 2022 - 04:39:08 EST


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;