# CVE-2026-99247: tracing: Do not initialize tracefs work if tracing is disabled

Status: published. Published: 2026-11-03. Updated: 2026-11-03.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < e8665e884e076d894f3eed8b9ea28e37a6448604 (affected, git); ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < e8cfcd7e60eaa3b0dea4d71c64499604e7081736 (affected, git); ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < afd38b10b1c6a5c5d6952b15b990596dab9684e6 (affected, git); ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < 813e18881c6472eb229a63180ff42c808e3e949b (affected, git); ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < 7539c61f522ff693d9565a0411386c2236e776cd (affected, git); ≥ 6621a7004684bfcff5af4c8e4d37989941f42a6b; < b3b974008388ab59e44d764ba7a63c988fec2524 (affected, git). Source: CNA: Linux
- Linux / Linux: 5.19 (affected); ≥ 0; < 5.19 (unaffected, semver); ≥ 6.1.191; ≤ 6.1.* (unaffected, semver); ≥ 6.6.161; ≤ 6.6.* (unaffected, semver); ≥ 6.12.115; ≤ 6.12.* (unaffected, semver); ≥ 6.18.59; ≤ 6.18.* (unaffected, semver); ≥ 7.2.13; ≤ 7.2.* (unaffected, semver); ≥ 7.3; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: Not reported

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://git.kernel.org/stable/c/e8665e884e076d894f3eed8b9ea28e37a6448604 (CNA: Linux)

- https://git.kernel.org/stable/c/e8cfcd7e60eaa3b0dea4d71c64499604e7081736 (CNA: Linux)

- https://git.kernel.org/stable/c/afd38b10b1c6a5c5d6952b15b990596dab9684e6 (CNA: Linux)

- https://git.kernel.org/stable/c/813e18881c6472eb229a63180ff42c808e3e949b (CNA: Linux)

- https://git.kernel.org/stable/c/7539c61f522ff693d9565a0411386c2236e776cd (CNA: Linux)

- https://git.kernel.org/stable/c/b3b974008388ab59e44d764ba7a63c988fec2524 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2026-99247; retrieved 2026-11-03; source updated 2026-11-03

Revision: d9e55df3b0356d541b907ee2abbfd1ed59bc15a4a5d341a9f7fab7c0ac656343

Canonical: https://y2.dev/cve/CVE-2026-99247

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