From c9299c86f4539a81d0b605cd6d2e801764cdfcb0 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 29 Jul 2019 21:47:52 +0800 Subject: [PATCH] netrom: hold sock when setting skb->destructor [ 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: Reported-and-tested-by: Reported-and-tested-by: Reported-and-tested-by: Cc: Ralf Baechle Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- net/netrom/af_netrom.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c index f11b6747e18c..43910e50752c 100644 --- a/net/netrom/af_netrom.c +++ b/net/netrom/af_netrom.c @@ -970,6 +970,7 @@ int nr_rx_frame(struct sk_buff *skb, struct net_device *dev) window = skb->data[20]; + sock_hold(make); skb->sk = make; skb->destructor = sock_efree; make->sk_state = TCP_ESTABLISHED; -- GitLab