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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-10-24 10:14:27 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-20 12:27:46 -0800
commit262eb452f9a806b1d115fffba520a496f62374b6 (patch)
tree25ed860a0306082f8f7e82e15a617f5472e78475
parent8ffff756458db53555ca36a97766f1731f6719cc (diff)
downloadvexpress-lsk-262eb452f9a806b1d115fffba520a496f62374b6.tar.gz
ipv6: reset dst.expires value when clearing expire flag
[ Upstream commit 01ba16d6ec85a1ec4669c75513a76b61ec53ee50 ] On receiving a packet too big icmp error we update the expire value by calling rt6_update_expires. This function uses dst_set_expires which is implemented that it can only reduce the expiration value of the dst entry. If we insert new routing non-expiry information into the ipv6 fib where we already have a matching rt6_info we only clear the RTF_EXPIRES flag in rt6i_flags and leave the dst.expires value as is. When new mtu information arrives for that cached dst_entry we again call dst_set_expires. This time it won't update the dst.expire value because we left the dst.expire value intact from the last update. So dst_set_expires won't touch dst.expires. Fix this by resetting dst.expires when clearing the RTF_EXPIRE flag. dst_set_expires checks for a zero expiration and updates the dst.expires. In the past this (not updating dst.expires) was necessary because dst.expire was placed in a union with the dst_entry *from reference and rt6_clean_expires did assign NULL to it. This split happend in ecd9883724b78cc72ed92c98bcb1a46c764fff21 ("ipv6: fix race condition regarding dst->expires and dst->from"). Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com> Reported-by: Valentijn Sessink <valentyn@blub.net> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Acked-by: Eric Dumazet <edumazet@google.com> Tested-by: Valentijn Sessink <valentyn@blub.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--include/net/ip6_fib.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 2a601e7da1b..665e0cee59b 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -165,6 +165,7 @@ static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
static inline void rt6_clean_expires(struct rt6_info *rt)
{
rt->rt6i_flags &= ~RTF_EXPIRES;
+ rt->dst.expires = 0;
}
static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)