In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_IDLETIMER: fix panic that occurs when timer_type has garbage value Currently, when the rule related to IDLETIMER is added, idletimer_tg timer structure is initialized by kmalloc on executing idletimer_tg_create function. However, in this process timer->timer_type is not defined to a specific value. Thus, timer->timer_type has garbage value and it occurs kernel panic. So, this commit fixes the panic by initializing timer->timer_type using kzalloc instead of kmalloc. Test commands: # iptables -A OUTPUT -j IDLETIMER --timeout 1 --label test $ cat /sys/class/xt_idletimer/timers/test Killed Splat looks like: BUG: KASAN: user-memory-access in alarm_expires_remaining+0x49/0x70 Read of size 8 at addr 0000002e8c7bc4c8 by task cat/917 CPU: 12 PID: 917 Comm: cat Not tainted 5.14.0+ #3 79940a339f71eb14fc81aee1757a20d5bf13eb0e Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS …