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| author | David Ahern <dsahern@kernel.org> | 2020-07-06 11:45:07 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-22 09:32:47 +0200 |
| commit | 75270f8196666c5bf4aeecacc08d114765931bee (patch) | |
| tree | f558917cb03afba7b7873926da92d9a454446aae /net | |
| parent | 1418b60e998b2c329e205a30ce85a4dfb9a40f68 (diff) | |
| download | linux-stable-75270f8196666c5bf4aeecacc08d114765931bee.tar.gz linux-stable-75270f8196666c5bf4aeecacc08d114765931bee.tar.bz2 linux-stable-75270f8196666c5bf4aeecacc08d114765931bee.zip | |
ipv6: fib6_select_path can not use out path for nexthop objects
[ Upstream commit 34fe5a1cf95c3f114068fc16d919c9cf4b00e428 ]
Brian reported a crash in IPv6 code when using rpfilter with a setup
running FRR and external nexthop objects. The root cause of the crash
is fib6_select_path setting fib6_nh in the result to NULL because of
an improper check for nexthop objects.
More specifically, rpfilter invokes ip6_route_lookup with flowi6_oif
set causing fib6_select_path to be called with have_oif_match set.
fib6_select_path has early check on have_oif_match and jumps to the
out label which presumes a builtin fib6_nh. This path is invalid for
nexthop objects; for external nexthops fib6_select_path needs to just
return if the fib6_nh has already been set in the result otherwise it
returns after the call to nexthop_path_fib6_result. Update the check
on have_oif_match to not bail on external nexthops.
Update selftests for this problem.
Fixes: f88d8ea67fbd ("ipv6: Plumb support for nexthop object in a fib6_info")
Reported-by: Brian Rak <brak@choopa.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/route.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3b4af0a8bca6..90042cad61ec 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -431,9 +431,12 @@ void fib6_select_path(const struct net *net, struct fib6_result *res, struct fib6_info *sibling, *next_sibling; struct fib6_info *match = res->f6i; - if ((!match->fib6_nsiblings && !match->nh) || have_oif_match) + if (!match->nh && (!match->fib6_nsiblings || have_oif_match)) goto out; + if (match->nh && have_oif_match && res->nh) + return; + /* We might have already computed the hash for ICMPv6 errors. In such * case it will always be non-zero. Otherwise now is the time to do it. */ |