CVE Catalog

CVE-2026-99247

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, if trace buffer allocation fails during early boot, tracing_disabled remains set and the global trace array events list stays uninitialized. tracer_init_tracefs_work_func() runs asynchronously without checking this state and calls event_trace_init() and init_tracer_tracefs(), leading to a NULL pointer dereference Oops during boot. The fix checks tracing_disabled at the start of the work function.

Risk Assessment

Systems may crash (kernel Oops) during boot, causing machine unavailability and requiring manual intervention. This particularly affects systems where trace buffer allocation failed due to memory constraints.

Recommendation

Update the Linux kernel to a version with the fix. For memory-constrained systems, consider increasing available resources or disabling tracing if not needed.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS