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| author | Stefano Brivio <sbrivio@redhat.com> | 2019-06-21 18:45:28 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-27 16:50:57 +0300 |
| commit | 50e10e08016039f97db670e8edbf6dbc2fe7c233 (patch) | |
| tree | 402b60acd4d357fe66ba9bdf193f0a0a96a3f321 /net/ipv6 | |
| parent | 62978761c8c6832e6f9c00d132e3d291357f1b17 (diff) | |
| download | linux-50e10e08016039f97db670e8edbf6dbc2fe7c233.tar.xz | |
ip6_fib: Don't discard nodes with valid routing information in fib6_locate_1()
[ Upstream commit 40cb35d5dc04e7f89cbc7b1fc9b4b48d9f1e5343 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/ip6_fib.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index bbb5ffb3397d..7091568b9f63 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -1529,7 +1529,8 @@ 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: /* |