From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 06/12] netfilter: conntrack: clamp timeouts to INT_MAX
Date: Wed, 13 Dec 2017 19:45:14 +0100 [thread overview]
Message-ID: <20171213184520.8193-7-pablo@netfilter.org> (raw)
In-Reply-To: <20171213184520.8193-1-pablo@netfilter.org>
From: Jay Elliott <jelliott@arista.com>
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: Jay Elliott <jelliott@arista.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_conntrack_netlink.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 59c08997bfdf..66d72a8fa87f 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -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]) {
--
2.11.0
next prev parent reply other threads:[~2017-12-13 18:45 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-13 18:45 [PATCH 00/12] Netfilter fixes for net Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 01/12] netfilter: remove redundant assignment to e Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 02/12] netfilter: exit_net cleanup check added Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 03/12] netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 04/12] netfilter: nf_ct_h323: Extend nf_h323_error_boundary to work on bits as well Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 05/12] netfilter: conntrack: lower timeout to RETRANS seconds if window is 0 Pablo Neira Ayuso
2017-12-13 18:45 ` Pablo Neira Ayuso [this message]
2017-12-13 18:45 ` [PATCH 07/12] netfilter: nfnetlink_cthelper: Add missing permission checks Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 08/12] netfilter: xt_bpf: add overflow checks Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 09/12] netfilter: xt_osf: Add missing permission checks Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 10/12] netfilter: ipt_CLUSTERIP: fix clusterip_net_exit build regression Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 11/12] netfilter: exthdr: add missign attributes to policy Pablo Neira Ayuso
2017-12-13 18:45 ` [PATCH 12/12] netfilter: ip6t_MASQUERADE: add dependency on conntrack module Pablo Neira Ayuso
2017-12-13 19:13 ` [PATCH 00/12] Netfilter fixes for net David Miller
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