{"id":"AZL-112601","summary":"CVE-2026-99247 affecting package kernel 6.6.159.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Do not initialize tracefs work if tracing is disabled\n\nIf trace buffer allocation fails during early boot (e.g.  in\nearly_trace_init() -\u003e allocate_trace_buffers()), tracing_disabled is\nleft set to 1 and the global trace array events list remains\nuninitialized.\n\nLater during boot, tracer_init_tracefs() (invoked via fs_initcall)\nqueues tracerfs_init_work asynchronously without checking if tracing was\ndisabled.  When tracer_init_tracefs_work_func() runs, it calls\nevent_trace_init() and init_tracer_tracefs(&global_trace, NULL)\nunconditionally.  This leads to __find_event_file() dereferencing an\nuninitialized tr-\u003eevents list, causing an early boot NULL pointer\ndereference Oops:\n\n  BUG: Kernel NULL pointer dereference on read at 0x00000010\n  Faulting instruction address: 0xc000000000485be0\n  Oops: Kernel access of bad area, sig: 7 [#1]\n  ...\n  NIP [c000000000485be0] __find_event_file+0x70/0x3c0\n  LR  [c000000000448874] init_tracer_tracefs+0x274/0xc80\n  Call Trace:\n   init_tracer_tracefs+0x274/0xc80\n   tracer_init_tracefs_work_func+0x50/0x320\n   process_one_work+0x1e8/0x5c0\n   worker_thread+0x1dc/0x3d0\n   kthread+0x194/0x1b0\n   start_kernel_thread+0x14/0x18\n\nCheck tracing_disabled at the beginning of tracer_init_tracefs_work_func()\nand return immediately if tracing is disabled or failed to initialize,\npreventing the crash.","modified":"2026-11-04T14:17:37.074031669Z","published":"2026-11-03T12:17:31Z","upstream":["CVE-2026-99247"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99247"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.159.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-112601.json"}}],"schema_version":"1.9.2"}