# CVE-2022-49764: bpf: Prevent bpf program recursion for raw tracepoint probes

Status: published. Published: 2025-05-01. Updated: 2026-11-05.

In the Linux kernel, the following vulnerability has been resolved:

bpf: Prevent bpf program recursion for raw tracepoint probes

We got report from sysbot [1] about warnings that were caused by
bpf program attached to contention_begin raw tracepoint triggering
the same tracepoint by using bpf_trace_printk helper that takes
trace_printk_lock lock.

 Call Trace:
  <TASK>
  ? trace_event_raw_event_bpf_trace_printk+0x5f/0x90
  bpf_trace_printk+0x2b/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  __unfreeze_partials+0x5b/0x160
  ...

The can be reproduced by attaching bpf program as raw tracepoint on
contention_begin tracepoint. The bpf prog calls bpf_trace_printk
helper. Then by running perf bench the spin lock code is forced to
take slow path and call contention_begin tracepoint.

Fixing this by skipping execution of the bpf program if it's
already running, Using bpf prog 'active' field, which is being
currently used by trampoline programs for the same reason.

Moving bpf_prog_inc_misses_counter to syscall.c because
trampoline.c is compiled in just for CONFIG_BPF_JIT option.

[1] https://lore.kernel.org/bpf/YxhFe3EwqchC%2FfYf@krava/T/#t

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Linux / Linux: ≥ c4f6699dfcb8558d138fe838f741b2c10f416cf9; < 2e5399879024fedd6cdc41f73fbf9bbe7208f899 (affected, git); ≥ c4f6699dfcb8558d138fe838f741b2c10f416cf9; < 05b24ff9b2cfabfcfd951daaa915a036ab53c9e1 (affected, git). Source: CNA: Linux
- Linux / Linux: 4.17 (affected); ≥ 0; < 4.17 (unaffected, semver); ≥ 6.0.10; ≤ 6.0.* (unaffected, semver); ≥ 6.1; ≤ * (unaffected, original_commit_for_fix). Source: CNA: Linux

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: 0.18% as of 2026-11-05; percentile 8.17%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- 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/2e5399879024fedd6cdc41f73fbf9bbe7208f899 (CNA: Linux)

- https://git.kernel.org/stable/c/05b24ff9b2cfabfcfd951daaa915a036ab53c9e1 (CNA: Linux)

## Provenance

- CNA: Linux: https://www.cve.org/CVERecord?id=CVE-2022-49764; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2022-49764; retrieved 2026-11-05; source updated Not reported

Revision: f069cb6a90c3b68f10bd9c7194976904a495f9fc8330ffd8e1a4a8c36052b7bc

Canonical: https://y2.dev/cve/CVE-2022-49764

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