[PATCH V2 resend] ipv6: fix incorrect route 'expires' value passed to userspace
flat view
STALE5183d
From: Li Wei <hidden>
Date: 2012-07-20 01:43:30
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
When userspace use RTM_GETROUTE to dump route table, with an 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 use the same trick as time_after macro to avoid the 'unsigned long' type promotion and deal with jiffies wrapping. Also we should do some fix in rtnl_put_cacheinfo() which use jiffies_to_clock_t(which take an unsigned long as parameter) to convert jiffies to clock_t to handle the negative expires. Signed-off-by: Li Wei <redacted> --- net/core/rtnetlink.c | 3 ++- net/ipv6/route.c | 7 ++++--- 2 files changed, 6 insertions(+), 4 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..7875255 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -2516,10 +2516,11 @@ 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) - expires = rt->dst.expires - jiffies; + else if ((long)rt->dst.expires - (long)jiffies > INT_MIN + && (long)rt->dst.expires - (long)jiffies < INT_MAX) + expires = (long)rt->dst.expires - (long)jiffies; else - expires = INT_MAX; + expires = time_is_after_jiffies(rt->dst.expires) ? INT_MAX : INT_MIN; peer = rt->rt6i_peer; ts = tsage = 0;
--
1.7.1