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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-10-24 10:14:27 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-20 12:27:46 -0800 |
| commit | 262eb452f9a806b1d115fffba520a496f62374b6 (patch) | |
| tree | 25ed860a0306082f8f7e82e15a617f5472e78475 | |
| parent | 8ffff756458db53555ca36a97766f1731f6719cc (diff) | |
| download | linux-3.10-262eb452f9a806b1d115fffba520a496f62374b6.tar.gz linux-3.10-262eb452f9a806b1d115fffba520a496f62374b6.tar.bz2 linux-3.10-262eb452f9a806b1d115fffba520a496f62374b6.zip | |
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.h | 1 |
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) |