From 3a8dd9711e0792f64394edafadd66c2d1f1904df Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Wed, 11 Mar 2015 15:43:55 -0400 Subject: [PATCH] sock: fix possible NULL sk dereference in __skb_tstamp_tx Test that sk != NULL before reading sk->sk_tsflags. Fixes: 49ca0d8bfaf3 ("net-timestamp: no-payload option") Reported-by: One Thousand Gnomes Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/core/skbuff.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 434e78e5254d..8e4ac97c8477 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3733,9 +3733,13 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, struct sock *sk, int tstype) { struct sk_buff *skb; - bool tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY; + bool tsonly; - if (!sk || !skb_may_tx_timestamp(sk, tsonly)) + if (!sk) + return; + + tsonly = sk->sk_tsflags & SOF_TIMESTAMPING_OPT_TSONLY; + if (!skb_may_tx_timestamp(sk, tsonly)) return; if (tsonly) -- 2.20.1