{"id":"AZL-106323","summary":"CVE-2026-98231 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: serialize state GC with device state flush\n\nThe deferred-device pass in xfrm_dev_state_flush() finds states under\nxfrm_state_dev_gc_lock, but drops the lock before calling\nxfrm_dev_state_free() because the driver callback may sleep.  The device\nGC list does not hold an xfrm_state reference, so the state GC worker can\ndestroy the same state concurrently.\n\nThe race can proceed as follows:\n\n  CPU 0                               CPU 1\n  find x on the device GC list\n  drop xfrm_state_dev_gc_lock\n  read x-\u003exso.dev\n                                      xfrm_state_gc_destroy(x)\n                                      xfrm_dev_state_free(x)\n                                      xfrm_state_free(x)\n  continue xfrm_dev_state_free(x)\n\nBoth paths can invoke the driver callback and drop the device reference.\nCPU 0 can also access the xfrm_state after CPU 1 has freed it.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in xfrm_dev_state_free+0x24c/0x2a0\n  Read of size 8 at addr ffff88810bbaa960 by task poc/102\n\n  Call Trace:\n   xfrm_dev_state_free+0x24c/0x2a0\n   xfrm_dev_state_flush+0x353/0x400\n   xfrm_dev_event+0x26d/0x3a0\n   notifier_call_chain+0xc0/0x280\n   __dev_notify_flags+0x169/0x250\n   netif_change_flags+0xe7/0x160\n   dev_change_flags+0x96/0x220\n   devinet_ioctl+0x7f4/0x1880\n\n  Allocated by task 87:\n   xfrm_state_alloc+0x1e/0x5c0\n   xfrm_add_sa+0xe7f/0x5820\n   xfrm_user_rcv_msg+0x4f3/0x940\n\n  Freed by task 57:\n   kmem_cache_free+0xcb/0x3d0\n   xfrm_state_gc_task+0x4a8/0x650\n   process_one_work+0x63a/0x1070\n\nSerialize xfrm_state destruction against the deferred-device pass with a\nmutex.  Keep xfrm_state_dev_gc_lock limited to list operations and retain\nthe existing callback and device-reference release ordering.","modified":"2026-10-07T14:17:02.484072396Z","published":"2026-10-06T09:18:10Z","upstream":["CVE-2026-98231"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98231"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-106323.json"}}],"schema_version":"1.9.0"}