CVE-2026-23274

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels<br /> <br /> IDLETIMER revision 0 rules reuse existing timers by label and always call<br /> mod_timer() on timer-&gt;timer.<br /> <br /> If the label was created first by revision 1 with XT_IDLETIMER_ALARM,<br /> the object uses alarm timer semantics and timer-&gt;timer is never initialized.<br /> Reusing that object from revision 0 causes mod_timer() on an uninitialized<br /> timer_list, triggering debugobjects warnings and possible panic when<br /> panic_on_warn=1.<br /> <br /> Fix this by rejecting revision 0 rule insertion when an existing timer with<br /> the same label is of ALARM type.