From 3e3be275851bc6fc90bfdcd732cd95563acd982b Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Wed, 7 Aug 2013 02:34:31 +0200 Subject: [PATCH] ipv6: don't stop backtracking in fib6_lookup_1 if subtree does not match In case a subtree did not match we currently stop backtracking and return NULL (root table from fib_lookup). This could yield in invalid routing table lookups when using subtrees. Instead continue to backtrack until a valid subtree or node is found and return this match. Also remove unneeded NULL check. Reported-by: Teco Boot Cc: YOSHIFUJI Hideaki Cc: David Lamparter Cc: Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/ip6_fib.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index bff3d821c7eb..c4ff5bbb45c4 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -993,14 +993,22 @@ static struct fib6_node * fib6_lookup_1(struct fib6_node *root, if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { #ifdef CONFIG_IPV6_SUBTREES - if (fn->subtree) - fn = fib6_lookup_1(fn->subtree, args + 1); + if (fn->subtree) { + struct fib6_node *sfn; + sfn = fib6_lookup_1(fn->subtree, + args + 1); + if (!sfn) + goto backtrack; + fn = sfn; + } #endif - if (!fn || fn->fn_flags & RTN_RTINFO) + if (fn->fn_flags & RTN_RTINFO) return fn; } } - +#ifdef CONFIG_IPV6_SUBTREES +backtrack: +#endif if (fn->fn_flags & RTN_ROOT) break;