From c65353daf137dd41f3ede3baf62d561fca076228 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 14 Apr 2011 05:55:37 +0000 Subject: [PATCH] ip: ip_options_compile() resilient to NULL skb route Scot Doyle demonstrated ip_options_compile() could be called with an skb without an attached route, using a setup involving a bridge, netfilter, and forged IP packets. Let's make ip_options_compile() and ip_options_rcv_srr() a bit more robust, instead of changing bridge/netfilter code. With help from Hiroaki SHIMODA. Reported-by: Scot Doyle Tested-by: Scot Doyle Signed-off-by: Eric Dumazet Cc: Stephen Hemminger Acked-by: Hiroaki SHIMODA Signed-off-by: David S. Miller --- net/ipv4/ip_options.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 28a736f3442f..2391b24e8251 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -329,7 +329,7 @@ int ip_options_compile(struct net *net, pp_ptr = optptr + 2; goto error; } - if (skb) { + if (rt) { memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); opt->is_changed = 1; } @@ -371,7 +371,7 @@ int ip_options_compile(struct net *net, goto error; } opt->ts = optptr - iph; - if (skb) { + if (rt) { memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); timeptr = (__be32*)&optptr[optptr[2]+3]; } @@ -603,7 +603,7 @@ int ip_options_rcv_srr(struct sk_buff *skb) unsigned long orefdst; int err; - if (!opt->srr) + if (!opt->srr || !rt) return 0; if (skb->pkt_type != PACKET_HOST) -- 2.20.1