From 02bcf4e082e4dc634409a6a6cb7def8806d6e5e6 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 11 Nov 2015 11:51:08 -0800 Subject: [PATCH] ipv6: Check rt->dst.from for the DST_NOCACHE route All DST_NOCACHE rt6_info used to have rt->dst.from set to its parent. After commit 8e3d5be73681 ("ipv6: Avoid double dst_free"), DST_NOCACHE is also set to rt6_info which does not have a parent (i.e. rt->dst.from is NULL). This patch catches the rt->dst.from == NULL case. Fixes: 8e3d5be73681 ("ipv6: Avoid double dst_free") Signed-off-by: Martin KaFai Lau Cc: Hannes Frederic Sowa Signed-off-by: David S. Miller --- include/net/ip6_fib.h | 3 ++- net/ipv6/route.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index aaf9700..fb961a5 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -167,7 +167,8 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) static inline u32 rt6_get_cookie(const struct rt6_info *rt) { - if (rt->rt6i_flags & RTF_PCPU || unlikely(rt->dst.flags & DST_NOCACHE)) + if (rt->rt6i_flags & RTF_PCPU || + (unlikely(rt->dst.flags & DST_NOCACHE) && rt->dst.from)) rt = (struct rt6_info *)(rt->dst.from); return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3754cf9..6f01fe1 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1281,7 +1281,8 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) rt6_dst_from_metrics_check(rt); - if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE)) + if (rt->rt6i_flags & RTF_PCPU || + (unlikely(dst->flags & DST_NOCACHE) && rt->dst.from)) return rt6_dst_from_check(rt, cookie); else return rt6_check(rt, cookie); -- 2.7.4