From: Tzung-Bi Shih tzungbi@kernel.org
[ Upstream commit 73db1b8f2bb6725b7391e85aab41fdf592b3c0c1 ]
(struct nf_conn)->timeout is an interval before the conntrack confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack: - Set by calling ctnetlink_change_timeout(). As a result, `nfct_time_stamp` was wrongly added to `ct->timeout` twice. - Get by calling ctnetlink_dump_timeout(). As a result, `nfct_time_stamp` was wrongly subtracted.
Call Trace: <TASK> dump_stack_lvl ctnetlink_dump_timeout __ctnetlink_glue_build ctnetlink_glue_build __nfqnl_enqueue_packet nf_queue nf_hook_slow ip_mc_output ? __pfx_ip_finish_output ip_send_skb ? __pfx_dst_output udp_send_skb udp_sendmsg ? __pfx_ip_generic_getfrag sock_sendmsg
Separate the 2 cases in: - Setting `ct->timeout` in __nf_ct_set_timeout(). - Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the introduction of the nfnetlink_queue conntrack support, select a sufficiently old Fixes: tag for -stable kernel to pick up this fix.
Fixes: a4b4766c3ceb ("netfilter: nfnetlink_queue: rename related to nfqueue attaching conntrack info") Signed-off-by: Tzung-Bi Shih tzungbi@kernel.org Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/netfilter/nf_conntrack_core.h | 6 +++++- net/netfilter/nf_conntrack_netlink.c | 13 +++++++++---- 2 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index 71d1269fe4d4f..3384859a89210 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -89,7 +89,11 @@ static inline void __nf_ct_set_timeout(struct nf_conn *ct, u64 timeout) { if (timeout > INT_MAX) timeout = INT_MAX; - WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout); + + if (nf_ct_is_confirmed(ct)) + WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout); + else + ct->timeout = (u32)timeout; }
int __nf_ct_change_timeout(struct nf_conn *ct, u64 cta_timeout); diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index d3ee188546982..6f3b23a6653cc 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -176,7 +176,12 @@ static int ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct) static int ctnetlink_dump_timeout(struct sk_buff *skb, const struct nf_conn *ct, bool skip_zero) { - long timeout = nf_ct_expires(ct) / HZ; + long timeout; + + if (nf_ct_is_confirmed(ct)) + timeout = nf_ct_expires(ct) / HZ; + else + timeout = ct->timeout / HZ;
if (skip_zero && timeout == 0) return 0; @@ -2253,9 +2258,6 @@ ctnetlink_create_conntrack(struct net *net, if (!cda[CTA_TIMEOUT]) goto err1;
- timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ; - __nf_ct_set_timeout(ct, timeout); - rcu_read_lock(); if (cda[CTA_HELP]) { char *helpname = NULL; @@ -2319,6 +2321,9 @@ ctnetlink_create_conntrack(struct net *net, /* we must add conntrack extensions before confirmation. */ ct->status |= IPS_CONFIRMED;
+ timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ; + __nf_ct_set_timeout(ct, timeout); + if (cda[CTA_STATUS]) { err = ctnetlink_change_status(ct, cda); if (err < 0)