CVE-2026-99247

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    CVE-2026-99247

    Published: 3 Nov 2026Last Modified: 5 Nov 2026

    Summary: tracing: Do not initialize tracefs work if tracing is disabled

    Details: In the Linux kernel, the following vulnerability has been resolved: tracing: Do not initialize tracefs work if tracing is disabled If trace buffer allocation fails during early boot (e.g. in early_trace_init() -> allocate_trace_buffers()), tracing_disabled is left set to 1 and the global trace array events list remains uninitialized. Later during boot, tracer_init_tracefs() (invoked via fs_initcall) queues tracerfs_init_work asynchronously without checking if tracing was disabled. When tracer_init_tracefs_work_func() runs, it calls event_trace_init() and init_tracer_tracefs(&global_trace, NULL) unconditionally. This leads to __find_event_file() dereferencing an uninitialized tr->events list, causing an early boot NULL pointer dereference Oops: BUG: Kernel NULL pointer dereference on read at 0x00000010 Faulting instruction address: 0xc000000000485be0 Oops: Kernel access of bad area, sig: 7 [#1] ... NIP [c000000000485be0] __find_event_file+0x70/0x3c0 LR [c000000000448874] init_tracer_tracefs+0x274/0xc80 Call Trace: init_tracer_tracefs+0x274/0xc80 tracer_init_tracefs_work_func+0x50/0x320 process_one_work+0x1e8/0x5c0 worker_thread+0x1dc/0x3d0 kthread+0x194/0x1b0 start_kernel_thread+0x14/0x18 Check tracing_disabled at the beginning of tracer_init_tracefs_work_func() and return immediately if tracing is disabled or failed to initialize, preventing the crash.

    References: https://git.kernel.org/stable/c/7539c61f522ff693d9565a0411386c2236e776cd, https://git.kernel.org/stable/c/813e18881c6472eb229a63180ff42c808e3e949b, https://git.kernel.org/stable/c/afd38b10b1c6a5c5d6952b15b990596dab9684e6, https://git.kernel.org/stable/c/b3b974008388ab59e44d764ba7a63c988fec2524, https://git.kernel.org/stable/c/e8665e884e076d894f3eed8b9ea28e37a6448604, https://git.kernel.org/stable/c/e8cfcd7e60eaa3b0dea4d71c64499604e7081736, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99247.json, https://nvd.nist.gov/vuln/detail/CVE-2026-99247, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 6621a7004684bfcff5af4c8e4d37989941f42a6b
    Fixed -e8665e884e076d894f3eed8b9ea28e37a6448604

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2026-99247 | CVE-DB