This is a note to let you know that I've just added the patch titled ipv6: Check rt->dst.from for the DST_NOCACHE route to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-check-rt-dst.from-for-the-dst_nocache-route.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Fri Dec 11 11:38:35 EST 2015 From: Martin KaFai Lau <kafai@xxxxxx> Date: Wed, 11 Nov 2015 11:51:08 -0800 Subject: ipv6: Check rt->dst.from for the DST_NOCACHE route From: Martin KaFai Lau <kafai@xxxxxx> [ Upstrem commit 02bcf4e082e4dc634409a6a6cb7def8806d6e5e6 ] 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 <kafai@xxxxxx> Cc: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/ip6_fib.h | 3 ++- net/ipv6/route.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -165,7 +165,8 @@ static inline void rt6_update_expires(st 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; --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1284,7 +1284,8 @@ static struct dst_entry *ip6_dst_check(s 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); Patches currently in stable-queue which might be from kafai@xxxxxx are queue-4.2/ipv6-check-rt-dst.from-for-the-dst_nocache-route.patch queue-4.2/ipv6-avoid-creating-rtf_cache-from-a-rt-that-is-not-managed-by-fib6-tree.patch queue-4.2/ipv6-check-expire-on-dst_nocache-route.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html