[PATCH net 1/9] rxrpc: Fix missing unlock in rxrpc_do_sendmsg()

From: David Howells
Date: Thu Dec 15 2022 - 11:20:47 EST


One of the error paths in rxrpc_do_sendmsg() doesn't unlock the call mutex
before returning. Fix it to do this.

Note that this still doesn't get rid of the checker warning:

../net/rxrpc/sendmsg.c:617:5: warning: context imbalance in 'rxrpc_do_sendmsg' - wrong count at exit

I think the interplay between the socket lock and the call's user_mutex may
be too complicated for checker to analyse, especially as
rxrpc_new_client_call_for_sendmsg(), which it calls, returns with the
call's user_mutex if successful but unconditionally drops the socket lock.

Fixes: e754eba685aa ("rxrpc: Provide a cmsg to specify the amount of Tx data for a call")
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---

net/rxrpc/sendmsg.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 9fa7e37f7155..cde1e65f16b4 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -625,7 +625,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
if (call->tx_total_len != -1 ||
call->tx_pending ||
call->tx_top != 0)
- goto error_put;
+ goto out_put_unlock;
call->tx_total_len = p.call.tx_total_len;
}
}