From: Jens Axboe <axboe@kernel.dk>
Date: Fri, 8 Mar 2024 00:48:03 +0000 (-0700)
Subject: io_uring/net: correctly handle multishot recvmsg retry setup
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=deaef31bc1ec7966698a427da8c161930830e1cf;p=linux.git

io_uring/net: correctly handle multishot recvmsg retry setup

If we loop for multishot receive on the initial attempt, and then abort
later on to wait for more, we miss a case where we should be copying the
io_async_msghdr from the stack to stable storage. This leads to the next
retry potentially failing, if the application had the msghdr on the
stack.

Cc: stable@vger.kernel.org
Fixes: 9bb66906f23e ("io_uring: support multishot in recvmsg")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/net.c b/io_uring/net.c
index e50947e7cd576..52f0d3b735fd0 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -931,7 +931,8 @@ retry_multishot:
 			kfree(kmsg->free_iov);
 		io_netmsg_recycle(req, issue_flags);
 		req->flags &= ~REQ_F_NEED_CLEANUP;
-	}
+	} else if (ret == -EAGAIN)
+		return io_setup_async_msg(req, kmsg, issue_flags);
 
 	return ret;
 }