io_uring/net: fix cleanup after recycle

Don't access io_async_msghdr io_netmsg_recycle(), it may be reallocated.

Cc: stable@vger.kernel.org
Fixes: 9bb66906 ("io_uring: support multishot in recvmsg")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/9e326f4ad4046ddadf15bf34bf3fa58c6372f6b5.1671461985.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/net.c

@@ -820,10 +820,10 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 		goto retry_multishot;
 
 	if (mshot_finished) {
-		io_netmsg_recycle(req, issue_flags);
 		/* fast path, check for non-NULL to avoid function call */
 		if (kmsg->free_iov)
 			kfree(kmsg->free_iov);
+		io_netmsg_recycle(req, issue_flags);
 		req->flags &= ~REQ_F_NEED_CLEANUP;
 	}