From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
[ Upstream commit 4638faac032756f7eab5524be7be56bee77e426b ]
sock_efree() releases the sock refcnt, if we don't hold this refcnt
when setting skb->destructor to it, the refcnt would not be balanced.
This leads to several bug reports from syzbot.
I have checked other users of sock_efree(), all of them hold the
sock refcnt.
Fixes: c8c8218ec5af ("netrom: fix a memory leak in nr_rx_frame()")
Reported-and-tested-by: <syzbot+622bdabb128acc33427d@xxxxxxxxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: <syzbot+6eaef7158b19e3fec3a0@xxxxxxxxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: <syzbot+9399c158fcc09b21d0d2@xxxxxxxxxxxxxxxxxxxxxxxxx>
Reported-and-tested-by: <syzbot+a34e5f3d0300163f0c87@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netrom/af_netrom.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -970,6 +970,7 @@ int nr_rx_frame(struct sk_buff *skb, str
window = skb->data[20];
+ sock_hold(make);
skb->sk = make;
skb->destructor = sock_efree;
make->sk_state = TCP_ESTABLISHED;
