1 From 673498b8ed4c4d4b7221c5309d891c5eac2b7528 Mon Sep 17 00:00:00 2001
2 From: Stefan Tomanek <stefan.tomanek@wertarbyte.de>
3 Date: Tue, 10 Dec 2013 23:21:25 +0100
4 Subject: [PATCH] inet: fix NULL pointer Oops in fib(6)_rule_suppress
6 This changes ensures that the routing entry investigated by the suppress
7 function actually does point to a device struct before following that pointer,
8 fixing a possible kernel oops situation when verifying the interface group
9 associated with a routing table entry.
11 According to Daniel Golle, this Oops can be triggered by a user process trying
12 to establish an outgoing IPv6 connection while having no real IPv6 connectivity
13 set up (only autoassigned link-local addresses).
15 Fixes: 6ef94cfafba15 ("fib_rules: add route suppression based on ifgroup")
17 Reported-by: Daniel Golle <daniel.golle@gmail.com>
18 Tested-by: Daniel Golle <daniel.golle@gmail.com>
19 Signed-off-by: Stefan Tomanek <stefan.tomanek@wertarbyte.de>
20 Signed-off-by: David S. Miller <davem@davemloft.net>
22 net/ipv4/fib_rules.c | 5 ++++-
23 net/ipv6/fib6_rules.c | 6 +++++-
24 2 files changed, 9 insertions(+), 2 deletions(-)
26 --- a/net/ipv4/fib_rules.c
27 +++ b/net/ipv4/fib_rules.c
28 @@ -104,7 +104,10 @@ errout:
29 static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
31 struct fib_result *result = (struct fib_result *) arg->result;
32 - struct net_device *dev = result->fi->fib_dev;
33 + struct net_device *dev = NULL;
36 + dev = result->fi->fib_dev;
38 /* do not accept result if the route does
39 * not meet the required prefix length
40 --- a/net/ipv6/fib6_rules.c
41 +++ b/net/ipv6/fib6_rules.c
42 @@ -122,7 +122,11 @@ out:
43 static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
45 struct rt6_info *rt = (struct rt6_info *) arg->result;
46 - struct net_device *dev = rt->rt6i_idev->dev;
47 + struct net_device *dev = NULL;
50 + dev = rt->rt6i_idev->dev;
52 /* do not accept result if the route does
53 * not meet the required prefix length