diff options
| author | Jay Elliott <jelliott@arista.com> | 2017-11-16 00:01:13 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-11-28 01:17:04 +0100 |
| commit | 8b1836c4b64386e9bc580438cae386ed31a43ab9 (patch) | |
| tree | 0d4f9364bc5ef3f6fbf1ed9ac464262b632f9ffd /net | |
| parent | netfilter: conntrack: lower timeout to RETRANS seconds if window is 0 (diff) | |
| download | linux-8b1836c4b64386e9bc580438cae386ed31a43ab9.tar.xz linux-8b1836c4b64386e9bc580438cae386ed31a43ab9.zip | |
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: Jay Elliott <jelliott@arista.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 12 |
1 files 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]) { |