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authorStefano Brivio <sbrivio@redhat.com>2019-06-21 18:45:28 +0300
committerDavid S. Miller <davem@davemloft.net>2019-06-24 20:18:49 +0300
commit40cb35d5dc04e7f89cbc7b1fc9b4b48d9f1e5343 (patch)
treeef0c902006fd79aa8c9ffac02e435301237748ef /net/ipv6
parent1e47b4837f3bdaa425727cfe09f5ae3b6c4c41a9 (diff)
downloadlinux-40cb35d5dc04e7f89cbc7b1fc9b4b48d9f1e5343.tar.xz
ip6_fib: Don't discard nodes with valid routing information in fib6_locate_1()
When we perform an inexact match on FIB nodes via fib6_locate_1(), longer prefixes will be preferred to shorter ones. However, it might happen that a node, with higher fn_bit value than some other, has no valid routing information. In this case, we'll pick that node, but it will be discarded by the check on RTN_RTINFO in fib6_locate(), and we might miss nodes with valid routing information but with lower fn_bit value. This is apparent when a routing exception is created for a default route: # ip -6 route list fc00:1::/64 dev veth_A-R1 proto kernel metric 256 pref medium fc00:2::/64 dev veth_A-R2 proto kernel metric 256 pref medium fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 pref medium fe80::/64 dev veth_A-R1 proto kernel metric 256 pref medium fe80::/64 dev veth_A-R2 proto kernel metric 256 pref medium default via fc00:1::2 dev veth_A-R1 metric 1024 pref medium # ip -6 route list cache fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 expires 593sec mtu 1500 pref medium fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 593sec mtu 1500 pref medium # ip -6 route flush cache # node for default route is discarded Failed to send flush request: No such process # ip -6 route list cache fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 586sec mtu 1500 pref medium Check right away if the node has a RTN_RTINFO flag, before replacing the 'prev' pointer, that indicates the longest matching prefix found so far. Fixes: 38fbeeeeccdb ("ipv6: prepare fib6_locate() for exception table") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/ip6_fib.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 0b68839b984b..49884f96232b 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1596,7 +1596,8 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root,
if (plen == fn->fn_bit)
return fn;
- prev = fn;
+ if (fn->fn_flags & RTN_RTINFO)
+ prev = fn;
next:
/*