-----Original Message-----
From: Eric Dumazet [mailto:<redacted>]
Sent: 14 May 2012 15:47
To: Pablo Neira Ayuso
Cc: David Laight; <redacted>;
davem@davemloft.net; netdev@vger.kernel.org; Jozsef Kadlecsik
Subject: Re: [PATCH 1/4] netfilter: ipset: fix timeout value
overflow bug
On Mon, 2012-05-14 at 16:36 +0200, Pablo Neira Ayuso wrote:
quoted
On Mon, May 14, 2012 at 03:19:49PM +0100, David Laight wrote:
quoted
quoted
--- 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
I was just reading the comment above - which seemed to imply
the purpose of the code was to ensure the timeout wouldn't
exceeded 2^32 jiffies.
I tend to use variable names for timeouts/timestamps that
include the units - can make it more obvious when a divisor
is absent - and makes it more obvious what the literal
constants are converying beween.
After all, the number of milliseconds in a second isn't
subject to change :-)
David