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authorXin Long <lucien.xin@gmail.com>2017-08-26 20:10:10 +0800
committerDavid S. Miller <davem@davemloft.net>2017-08-28 15:45:04 -0700
commit1e2ea8ad37be25a7cdcc974945935829d534d5d3 (patch)
tree3dd8203c3b1ecc7bb312a1073e82c454531dcd49 /net
parent4e587ea71bf924f7dac621f1351653bd41e446cb (diff)
downloadlinux-1e2ea8ad37be25a7cdcc974945935829d534d5d3.tar.bz2
ipv6: set dst.obsolete when a cached route has expired
Now it doesn't check for the cached route expiration in ipv6's dst_ops->check(), because it trusts dst_gc that would clean the cached route up when it's expired. The problem is in dst_gc, it would clean the cached route only when it's refcount is 1. If some other module (like xfrm) keeps holding it and the module only release it when dst_ops->check() fails. But without checking for the cached route expiration, .check() may always return true. Meanwhile, without releasing the cached route, dst_gc couldn't del it. It will cause this cached route never to expire. This patch is to set dst.obsolete with DST_OBSOLETE_KILL in .gc when it's expired, and check obsolete != DST_OBSOLETE_FORCE_CHK in .check. Note that this is even needed when ipv6 dst_gc timer is removed one day. It would set dst.obsolete in .redirect and .update_pmtu instead, and check for cached route expiration when getting it, just like what ipv4 route does. Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv6/ip6_fib.c4
-rw-r--r--net/ipv6/route.c3
2 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 10b4b1f8b838..e1c85bb4eac0 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1795,8 +1795,10 @@ static int fib6_age(struct rt6_info *rt, void *arg)
}
gc_args->more++;
} else if (rt->rt6i_flags & RTF_CACHE) {
+ if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout))
+ rt->dst.obsolete = DST_OBSOLETE_KILL;
if (atomic_read(&rt->dst.__refcnt) == 1 &&
- time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
+ rt->dst.obsolete == DST_OBSOLETE_KILL) {
RT6_TRACE("aging clone %p\n", rt);
return -1;
} else if (rt->rt6i_flags & RTF_GATEWAY) {
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 86fb2411e2bd..2d0e7798c793 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -440,7 +440,8 @@ static bool rt6_check_expired(const struct rt6_info *rt)
if (time_after(jiffies, rt->dst.expires))
return true;
} else if (rt->dst.from) {
- return rt6_check_expired((struct rt6_info *) rt->dst.from);
+ return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
+ rt6_check_expired((struct rt6_info *)rt->dst.from);
}
return false;
}