{"id":"CVE-2026-99247","title":"tracing: Do not initialize tracefs work if tracing is disabled","summary":"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() -> allocate_trace_buffer…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < e8665e884e076d894f3eed8b9ea28e37a6448604","Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < e8cfcd7e60eaa3b0dea4d71c64499604e7081736","Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < afd38b10b1c6a5c5d6952b15b990596dab9684e6","Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < 813e18881c6472eb229a63180ff42c808e3e949b","Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < 7539c61f522ff693d9565a0411386c2236e776cd","Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < b3b974008388ab59e44d764ba7a63c988fec2524","Linux 5.19"],"published":"2026-11-03","updated":"2026-11-03","sourceUpdated":"2026-11-03T11:18:26.163Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99247","references":[{"url":"https://git.kernel.org/stable/c/e8665e884e076d894f3eed8b9ea28e37a6448604"},{"url":"https://git.kernel.org/stable/c/e8cfcd7e60eaa3b0dea4d71c64499604e7081736"},{"url":"https://git.kernel.org/stable/c/afd38b10b1c6a5c5d6952b15b990596dab9684e6"},{"url":"https://git.kernel.org/stable/c/813e18881c6472eb229a63180ff42c808e3e949b"},{"url":"https://git.kernel.org/stable/c/7539c61f522ff693d9565a0411386c2236e776cd"},{"url":"https://git.kernel.org/stable/c/b3b974008388ab59e44d764ba7a63c988fec2524"}],"tags":["cve.org"],"epss":0.00161,"epssPercentile":0.05339,"ingestedAt":"2026-11-05T19:30:42.936Z","slug":"CVE-2026-99247","body":"## Overview\n\nIn 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() -> 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->events 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.\n\n## Affected\n\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < e8665e884e076d894f3eed8b9ea28e37a6448604`\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < e8cfcd7e60eaa3b0dea4d71c64499604e7081736`\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < afd38b10b1c6a5c5d6952b15b990596dab9684e6`\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < 813e18881c6472eb229a63180ff42c808e3e949b`\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < 7539c61f522ff693d9565a0411386c2236e776cd`\n- `Linux >= 6621a7004684bfcff5af4c8e4d37989941f42a6b < b3b974008388ab59e44d764ba7a63c988fec2524`\n- `Linux 5.19`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}