In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: fix wrong ct->timeout value (struct nfconn)->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 ctnetlinkchangetimeout(). As a result, nfct_time_stamp was wrongly added to ct->timeout twice. - Get by calling ctnetlinkdumptimeout(). As a result, nfct_time_stamp was wrongly subtracted. Call Trace: <TASK> dumpstacklvl ctnetlinkdumptimeout _ctnetlinkgluebuild ctnetlinkgluebuild _nfqnlenqueuepacket nfqueue nfhookslow ipmcoutput ? _pfxipfinishoutput ipsendskb ? _pfxdstoutput udpsendskb udpsendmsg ? _pfxipgenericgetfrag socksendmsg Separate the 2 cases in: - Setting ct->timeout in _nfctsettimeout(). - Getting ct->timeout in ctnetlinkdumptimeout(). Pablo appends: Update ctnetlink to set up the timeout _after the IPSCONFIRMED flag is set on, otherwise conntrack creation via ctnetlink breaks. Note that the problem described in this patch occurs since the introduction of the nfnetlinkqueue conntrack support, select a sufficiently old Fixes: tag for -stable kernel to pick up this fix.