Re: [syzbot] WARNING: bad unlock balance in rxrpc_do_sendmsg

From: Khalid Masum
Date: Sun Aug 21 2022 - 15:18:14 EST


Maybe we do not need to lock since no other timer_schedule needs
it.

Test if this fixes the issue.
---
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 568035b01cfb
net/rxrpc/sendmsg.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 1d38e279e2ef..640e2ab2cc35 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -51,10 +51,8 @@ static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
return sock_intr_errno(*timeo);

trace_rxrpc_transmit(call, rxrpc_transmit_wait);
- mutex_unlock(&call->user_mutex);
*timeo = schedule_timeout(*timeo);
- if (mutex_lock_interruptible(&call->user_mutex) < 0)
- return sock_intr_errno(*timeo);
+ return sock_intr_errno(*timeo);
}
}

--
2.37.1