{"id":"AZL-97266","summary":"CVE-2026-74726 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: alb: re-check primary_is_promisc under RTNL in bond_alb_monitor\n\nbond_alb_monitor() reads primary_is_promisc under RCU, then drops RCU and\ntakes RTNL via rtnl_trylock() before undoing the promiscuity it set on the\nactive slave. In that window the active slave can change under RTNL\n(RTM_DELLINK -\u003e __bond_release_one() -\u003e bond_alb_handle_active_change()),\nwhich already drops the promiscuity and clears primary_is_promisc. The\nmonitor still acts on the stale decision: if the slave was removed with no\nfailover, curr_active_slave is now NULL and the deref faults; if it failed\nover, the stale dev_set_promiscuity(-1) underflows the new slave's\npromiscuity counter and pins it in IFF_PROMISC.\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n  Workqueue: b42 bond_alb_monitor\n  RIP: 0010:bond_alb_monitor (drivers/net/bonding/bond_alb.c:1600)\n   process_one_work (kernel/workqueue.c:3322)\n   worker_thread (kernel/workqueue.c:3486)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n  Kernel panic - not syncing: Fatal exception\n\nRe-check primary_is_promisc (and curr_active_slave) after taking RTNL so\nthe monitor only undoes an increment it still owns. The other bonding\nmonitors already re-read state under RTNL in their commit phase\n(bond_miimon_commit/bond_ab_arp_commit); bond_alb_monitor() was the only\none acting on the pre-trylock decision.","modified":"2026-09-14T05:26:59Z","published":"2026-08-22T16:16:47Z","upstream":["CVE-2026-74726"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74726"}],"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-97266.json"}}],"schema_version":"1.9.0"}