From: Li Wei <lw@cn•fujitsu.com>
To: "David S. Miller" <davem@davemloft•net>
Cc: netdev <netdev@vger•kernel.org>,
Stephen Hemminger <shemminger@vyatta•com>
Subject: [PATCH] ipv6: fix incorrect route 'expires' value passed to userspace.
Date: Mon, 16 Jul 2012 16:09:37 +0800 [thread overview]
Message-ID: <5003CC41.9080204@cn.fujitsu.com> (raw)
When userspace use RTM_GETROUTE to dump route table, with a already
expired route entry, we always got an 'expires' value(2147157)
calculated base on INT_MAX.
The reason of this problem is in the following satement:
rt->dst.expires - jiffies < INT_MAX
gcc promoted the type of both sides of '<' to unsigned long, thus
a small negative value would be considered greater than INT_MAX.
This patch fix this by cast the result of subtraction to an 'int'
which I think is large enough for the expires.
Also we should do some fix in rtnl_put_cacheinfo() which use
jiffies_to_clock_t(which take an unsigned log as parameter) to
convert jiffies to clock_t to handle the negative expires.
---
net/core/rtnetlink.c | 3 ++-
net/ipv6/route.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 21318d1..f92f3d8 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -641,7 +641,8 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
};
if (expires)
- ci.rta_expires = jiffies_to_clock_t(expires);
+ ci.rta_expires = expires > 0 ? jiffies_to_clock_t(expires)
+ : -jiffies_to_clock_t(-expires);
return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index becb048..a7fec9d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2516,7 +2516,7 @@ static int rt6_fill_node(struct net *net,
goto nla_put_failure;
if (!(rt->rt6i_flags & RTF_EXPIRES))
expires = 0;
- else if (rt->dst.expires - jiffies < INT_MAX)
+ else if ((int)(rt->dst.expires - jiffies) < INT_MAX)
expires = rt->dst.expires - jiffies;
else
expires = INT_MAX;
--
1.7.1
next reply other threads:[~2012-07-16 8:10 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-16 8:09 Li Wei [this message]
2012-07-16 9:56 ` [PATCH] ipv6: fix incorrect route 'expires' value passed to userspace David Miller
2012-07-17 1:55 ` Li Wei
2012-07-19 2:02 ` [PATCH V2] " Li Wei
2012-07-19 17:49 ` David Miller
2012-07-20 1:32 ` Li Wei
2012-07-20 1:42 ` [PATCH V2 resend] " Li Wei
2012-07-20 10:32 ` David Laight
2012-07-20 18:22 ` David Miller
2012-07-23 1:05 ` Li Wei
2012-07-25 5:25 ` [PATCH V3] " Li Wei
2012-07-25 6:51 ` Eric Dumazet
2012-07-25 7:33 ` Li Wei
2012-07-30 2:01 ` [PATCH v4] " Li Wei
2012-07-30 6:20 ` David Miller
2012-07-23 1:02 ` [PATCH V2 resend] " Li Wei
2012-07-16 16:41 ` [PATCH] " Stephen Hemminger
2012-07-17 1:53 ` Li Wei
2012-07-17 5:26 ` David Miller
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