DEBIAN-CVE-2026-23274

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