niph is not updated after pskb_expand_head changes the skb head. It still points to the freed data, which is then used to update tot_len and checksum. This could cause use-after-free poison crash. Update niph, if ip_route_me_harder does not fail. Signed-off-by: Tejaswi Tanikella <tejaswit@xxxxxxxxxxxxxx> --- net/ipv4/netfilter/nf_reject_ipv4.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c index eeacbda..b2e0f90 100644 --- a/net/ipv4/netfilter/nf_reject_ipv4.c +++ b/net/ipv4/netfilter/nf_reject_ipv4.c @@ -131,6 +131,8 @@ void nf_send_reset(struct net *net, struct sk_buff *oldskb, int hook) if (ip_route_me_harder(net, nskb, RTN_UNSPEC)) goto free_nskb; + else + niph = ip_hdr(nskb); /* "Never happens" */ if (nskb->len > dst_mtu(skb_dst(nskb))) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html