CVE-2026-72321 ipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer()

In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: Fix potential memory leaks in igmpmodtimer and igmpstoptimer When a timer is deleted and not re-armed in igmpmodtimer, or stopped in igmpstoptimer, the code currently decrements the reference counter of the multicast...