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authorWANG Cong <xiyou.wangcong@gmail.com>2017-02-27 16:07:43 -0800
committerDavid S. Miller <davem@davemloft.net>2017-03-02 12:43:47 -0800
commite3330039ea28dc199e3b2da993895ff742a91adf (patch)
treee2755e80b6742c3f4b8a82464210f52c87b20e65
parent48cac18ecf1de82f76259a54402c3adb7839ad01 (diff)
downloadlinux-e3330039ea28dc199e3b2da993895ff742a91adf.tar.gz
ipv6: check for ip6_null_entry in __ip6_del_rt_siblings()
Andrey reported a NULL pointer deref bug in ipv6_route_ioctl() -> ip6_route_del() -> __ip6_del_rt_siblings() code path. This is because ip6_null_entry is returned in this path since ip6_null_entry is kinda default for a ipv6 route table root node. Quote from David Ahern: ip6_null_entry is the root of all ipv6 fib tables making it integrated into the table ... We should ignore any attempt of trying to delete it, like we do in __ip6_del_rt() path and several others. Reported-by: Andrey Konovalov <andreyknvl@google.com> Fixes: 0ae8133586ad ("net: ipv6: Allow shorthand delete of all nexthops in multipath route") Cc: David Ahern <dsa@cumulusnetworks.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv6/route.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d94f1df..43ca90d5 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2169,10 +2169,13 @@ int ip6_del_rt(struct rt6_info *rt)
static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
{
struct nl_info *info = &cfg->fc_nlinfo;
+ struct net *net = info->nl_net;
struct sk_buff *skb = NULL;
struct fib6_table *table;
- int err;
+ int err = -ENOENT;
+ if (rt == net->ipv6.ip6_null_entry)
+ goto out_put;
table = rt->rt6i_table;
write_lock_bh(&table->tb6_lock);
@@ -2184,7 +2187,7 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
if (skb) {
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
- if (rt6_fill_node(info->nl_net, skb, rt,
+ if (rt6_fill_node(net, skb, rt,
NULL, NULL, 0, RTM_DELROUTE,
info->portid, seq, 0) < 0) {
kfree_skb(skb);
@@ -2198,17 +2201,18 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
rt6i_siblings) {
err = fib6_del(sibling, info);
if (err)
- goto out;
+ goto out_unlock;
}
}
err = fib6_del(rt, info);
-out:
+out_unlock:
write_unlock_bh(&table->tb6_lock);
+out_put:
ip6_rt_put(rt);
if (skb) {
- rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV6_ROUTE,
+ rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
info->nlh, gfp_any());
}
return err;