From 673498b8ed4c4d4b7221c5309d891c5eac2b7528 Mon Sep 17 00:00:00 2001 From: Stefan Tomanek Date: Tue, 10 Dec 2013 23:21:25 +0100 Subject: inet: fix NULL pointer Oops in fib(6)_rule_suppress This changes ensures that the routing entry investigated by the suppress function actually does point to a device struct before following that pointer, fixing a possible kernel oops situation when verifying the interface group associated with a routing table entry. According to Daniel Golle, this Oops can be triggered by a user process trying to establish an outgoing IPv6 connection while having no real IPv6 connectivity set up (only autoassigned link-local addresses). Fixes: 6ef94cfafba15 ("fib_rules: add route suppression based on ifgroup") Reported-by: Daniel Golle Tested-by: Daniel Golle Signed-off-by: Stefan Tomanek Signed-off-by: David S. Miller --- net/ipv6/fib6_rules.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net/ipv6/fib6_rules.c') diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index e275916..3fd0a57 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -122,7 +122,11 @@ out: static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg) { struct rt6_info *rt = (struct rt6_info *) arg->result; - struct net_device *dev = rt->rt6i_idev->dev; + struct net_device *dev = NULL; + + if (rt->rt6i_idev) + dev = rt->rt6i_idev->dev; + /* do not accept result if the route does * not meet the required prefix length */ -- cgit v1.1