Commit 02bcf4e0 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller

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 8e3d5be7 ("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: 8e3d5be7 ("ipv6: Avoid double dst_free")
Signed-off-by: default avatarMartin KaFai Lau <>
Cc: Hannes Frederic Sowa <>
Signed-off-by: default avatarDavid S. Miller <>
parent 5973fb1e
......@@ -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;
......@@ -1281,7 +1281,8 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
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);
return rt6_check(rt, cookie);
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