Commit 8b1836c4 authored by Jay Elliott's avatar Jay Elliott Committed by Pablo Neira Ayuso

netfilter: conntrack: clamp timeouts to INT_MAX

When the conntracking code multiplies a timeout by HZ, it can overflow
from positive to negative; this causes it to instantly expire.  To
protect against this the multiplication is done in 64-bit so we can
prevent it from exceeding INT_MAX.
Signed-off-by: default avatarJay Elliott <jelliott@arista.com>
Acked-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent fbcd253d
......@@ -1566,9 +1566,11 @@ static int ctnetlink_change_helper(struct nf_conn *ct,
static int ctnetlink_change_timeout(struct nf_conn *ct,
const struct nlattr * const cda[])
{
u_int32_t timeout = ntohl(nla_get_be32(cda[CTA_TIMEOUT]));
u64 timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
ct->timeout = nfct_time_stamp + timeout * HZ;
if (timeout > INT_MAX)
timeout = INT_MAX;
ct->timeout = nfct_time_stamp + (u32)timeout;
if (test_bit(IPS_DYING_BIT, &ct->status))
return -ETIME;
......@@ -1768,6 +1770,7 @@ ctnetlink_create_conntrack(struct net *net,
int err = -EINVAL;
struct nf_conntrack_helper *helper;
struct nf_conn_tstamp *tstamp;
u64 timeout;
ct = nf_conntrack_alloc(net, zone, otuple, rtuple, GFP_ATOMIC);
if (IS_ERR(ct))
......@@ -1776,7 +1779,10 @@ ctnetlink_create_conntrack(struct net *net,
if (!cda[CTA_TIMEOUT])
goto err1;
ct->timeout = nfct_time_stamp + ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
if (timeout > INT_MAX)
timeout = INT_MAX;
ct->timeout = (u32)timeout + nfct_time_stamp;
rcu_read_lock();
if (cda[CTA_HELP]) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment