On Mon, May 14, 2012 at 07:45:07PM +0200, Jozsef Kadlecsik wrote:
> On Mon, 14 May 2012, Eric Dumazet wrote:
>
> > On Mon, 2012-05-14 at 16:36 +0200, Pablo Neira Ayuso wrote:
> > > On Mon, May 14, 2012 at 03:19:49PM +0100, David Laight wrote:
> > > >
> > > > > --- a/include/linux/netfilter/ipset/ip_set_timeout.h
> > > > > +++ b/include/linux/netfilter/ipset/ip_set_timeout.h
> > > > > @@ -30,6 +30,10 @@ ip_set_timeout_uget(struct nlattr *tb)
> > > > > {
> > > > > unsigned int timeout = ip_set_get_h32(tb);
> > > > >
> > > > > + /* Normalize to fit into jiffies */
> > > > > + if (timeout > UINT_MAX/1000)
> > > > > + timeout = UINT_MAX/1000;
> > > > > +
> > > >
> > > > Doesn't that rather assume that HZ is 1000 ?
> > >
> > > Indeed. I overlooked that. Thanks David.
> >
> > I dont think so.
> >
> > 1000 here is really MSEC_PER_SEC
> >
> > (All occurrences should be changed in this file)
>
> Yes, exactly. Pablo, shall I produce a little patch or could you change
> 1000 to MSEC_PER_SEC?
New patch attached.
I have rebase my tree again.
>From 9fdc90b2d00ecf98797c147d58cfe324fc92c9ed Mon Sep 17 00:00:00 2001
From: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
Date: Mon, 7 May 2012 02:35:44 +0000
Subject: [PATCH] netfilter: ipset: fix timeout value overflow bug
Large timeout parameters could result wrong timeout values due to
an overflow at msec to jiffies conversion (reported by Andreas Herz)
[ This patch was mangled by Pablo Neira Ayuso since David Laight and
Eric Dumazet noticed that we were using hardcoded 1000 instead of
MSEC_PER_SEC to calculate the timeout ]
Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/linux/netfilter/ipset/ip_set_timeout.h | 4 ++++
net/netfilter/xt_set.c | 15 +++++++++++++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/include/linux/netfilter/ipset/ip_set_timeout.h b/include/linux/netfilter/ipset/ip_set_timeout.h
index 4792320..41d9cfa 100644
--- a/include/linux/netfilter/ipset/ip_set_timeout.h
+++ b/include/linux/netfilter/ipset/ip_set_timeout.h
@@ -30,6 +30,10 @@ ip_set_timeout_uget(struct nlattr *tb)
{
unsigned int timeout = ip_set_get_h32(tb);
+ /* Normalize to fit into jiffies */
+ if (timeout > UINT_MAX/MSEC_PER_SEC)
+ timeout = UINT_MAX/MSEC_PER_SEC;
+
/* Userspace supplied TIMEOUT parameter: adjust crazy size */
return timeout == IPSET_NO_TIMEOUT ? IPSET_NO_TIMEOUT - 1 : timeout;
}
diff --git a/net/netfilter/xt_set.c b/net/netfilter/xt_set.c
index 0ec8138..035960e 100644
--- a/net/netfilter/xt_set.c
+++ b/net/netfilter/xt_set.c
@@ -44,6 +44,14 @@ const struct ip_set_adt_opt n = { \
.cmdflags = cfs, \
.timeout = t, \
}
+#define ADT_MOPT(n, f, d, fs, cfs, t) \
+struct ip_set_adt_opt n = { \
+ .family = f, \
+ .dim = d, \
+ .flags = fs, \
+ .cmdflags = cfs, \
+ .timeout = t, \
+}
/* Revision 0 interface: backward compatible with netfilter/iptables */
@@ -296,11 +304,14 @@ static unsigned int
set_target_v2(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_set_info_target_v2 *info = par->targinfo;
- ADT_OPT(add_opt, par->family, info->add_set.dim,
- info->add_set.flags, info->flags, info->timeout);
+ ADT_MOPT(add_opt, par->family, info->add_set.dim,
+ info->add_set.flags, info->flags, info->timeout);
ADT_OPT(del_opt, par->family, info->del_set.dim,
info->del_set.flags, 0, UINT_MAX);
+ /* Normalize to fit into jiffies */
+ if (add_opt.timeout > UINT_MAX/MSEC_PER_SEC)
+ add_opt.timeout = UINT_MAX/MSEC_PER_SEC;
if (info->add_set.index != IPSET_INVALID_ID)
ip_set_add(info->add_set.index, skb, par, &add_opt);
if (info->del_set.index != IPSET_INVALID_ID)
--
1.7.10
