{"id":"AZL-96117","summary":"CVE-2026-72321 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: igmp: Fix potential memory leaks in igmp_mod_timer() and igmp_stop_timer()\n\nWhen a timer is deleted and not re-armed in igmp_mod_timer(), or stopped\nin igmp_stop_timer(), the code currently decrements the reference counter\nof the multicast list entry @im using refcount_dec(&im-\u003erefcnt).\n\nHowever, both functions can be called from the RCU reader path:\n- igmp_mod_timer() via igmp_heard_query() -\u003e for_each_pmc_rcu()\n- igmp_stop_timer() via igmp_rcv() -\u003e igmp_heard_report()\n\nIf the group im was concurrently removed from the list by ip_mc_dec_group(),\nits reference count might have already been decremented to 1.\n\nIn this case, timer_delete() succeeds, and refcount_dec() decrements\nthe refcount from 1 to 0. Since refcount_dec() does not free the object\nwhen it hits 0 (unlike ip_ma_put()), the im structure is leaked.\n\nFix this by using ip_ma_put(im) instead of refcount_dec(&im-\u003erefcnt),\nand deferring the put until after the spinlock is released.","modified":"2026-09-04T05:27:10Z","published":"2026-08-15T06:22:05Z","upstream":["CVE-2026-72321"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72321"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-96117.json"}}],"schema_version":"1.9.0"}