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authorPaolo Abeni <pabeni@redhat.com>2019-02-21 11:19:42 +0100
committerDavid S. Miller <davem@davemloft.net>2019-02-21 09:54:35 -0800
commitbf1dc8bad1d42287164d216d8efb51c5cd381b18 (patch)
tree215c82e1182600e409e4b623b7d026671d071582 /net/ipv6
parent193f3685d0546b0cea20c99894aadb70098e47bf (diff)
downloadlinux-bf1dc8bad1d42287164d216d8efb51c5cd381b18.tar.bz2
ipv6: route: enforce RCU protection in ip6_route_check_nh_onlink()
We need a RCU critical section around rt6_info->from deference, and proper annotation. Fixes: 4ed591c8ab44 ("net/ipv6: Allow onlink routes to have a device mismatch if it is the default route") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/route.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2b1ed8c6fcab..74b9b6fd4168 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2743,20 +2743,24 @@ static int ip6_route_check_nh_onlink(struct net *net,
u32 tbid = l3mdev_fib_table(dev) ? : RT_TABLE_MAIN;
const struct in6_addr *gw_addr = &cfg->fc_gateway;
u32 flags = RTF_LOCAL | RTF_ANYCAST | RTF_REJECT;
+ struct fib6_info *from;
struct rt6_info *grt;
int err;
err = 0;
grt = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0);
if (grt) {
+ rcu_read_lock();
+ from = rcu_dereference(grt->from);
if (!grt->dst.error &&
/* ignore match if it is the default route */
- grt->from && !ipv6_addr_any(&grt->from->fib6_dst.addr) &&
+ from && !ipv6_addr_any(&from->fib6_dst.addr) &&
(grt->rt6i_flags & flags || dev != grt->dst.dev)) {
NL_SET_ERR_MSG(extack,
"Nexthop has invalid gateway or device mismatch");
err = -EINVAL;
}
+ rcu_read_unlock();
ip6_rt_put(grt);
}