Description
In the Linux kernel, the following vulnerability has been resolved:
acpi: typec: ucsi: Introduce a ->poll_cci method
For the ACPI backend of UCSI the UCSI "registers" are just a memory copy
of the register values in an opregion. The ACPI implementation in the
BIOS ensures that the opregion contents are synced to the embedded
controller and it ensures that the registers (in particular CCI) are
synced back to the opregion on notifications. While there is an ACPI call
that syncs the actual registers to the opregion there is rarely a need to
do this and on some ACPI implementations it actually breaks in various
interesting ways.
The only reason to force a sync from the embedded controller is to poll
CCI while notifications are disabled. Only the ucsi core knows if this
is the case and guessing based on the current command is suboptimal, i.e.
leading to the following spurious assertion splat:
WARNING: CPU: 3 PID: 76 at drivers/usb/typec/ucsi/ucsi.c:1388 ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]
CPU: 3 UID: 0 PID: 76 Comm: kworker/3:0 Not tainted 6.12.11-200.fc41.x86_64 #1
Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN45WW 03/17/2023
Workqueue: events_long ucsi_init_work [typec_ucsi]
RIP: 0010:ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]
Call Trace:
<TASK>
ucsi_init_work+0x3c/0xac0 [typec_ucsi]
process_one_work+0x179/0x330
worker_thread+0x252/0x390
kthread+0xd2/0x100
ret_from_fork+0x34/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
Thus introduce a ->poll_cci() method that works like ->read_cci() with an
additional forced sync and document that this should be used when polling
with notifications disabled. For all other backends that presumably don't
have this issue use the same implementation for both methods.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.12.5 – < 6.12.19, 6.13 | 6.12.19 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.12.19-1 | — |
| Debian 13 | linux | 6.12.19-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-azure-6.11 | 6.11.0-1018.18~24.04.1 | USN-7628-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.11 | 6.11.0-1016.16~24.04.1 | USN-7605-1 |
| Ubuntu 24.04 LTS | linux-hwe-6.11 | 6.11.0-28.28~24.04.1 | USN-7605-1 |
| Ubuntu 24.04 LTS | linux-lowlatency-hwe-6.11 | 6.11.0-1015.16~24.04.2 | USN-7605-2 |
| Ubuntu 24.04 LTS | linux-nvidia-6.11 | 6.11.0-1012.12 | — |
| Ubuntu 24.04 LTS | linux-oem-6.11 | 6.11.0-1021.21 | USN-7491-1 |
| Ubuntu 24.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rv +76 | 6.12.0-124.8.1.el10_1 | RHSA-2025:20095 |
| RHEL 9 | rv +75 | 5.14.0-611.5.1.el9_7 | RHSA-2025:20518 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-101.33.4.3.el10uek | ELSA-2025-20530, ELSA-2025-20480 |
Advisories 9
- WID-SEC-2025-0683 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- USN-7628-1 linux-azure, linux-azure-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7605-1 linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oracle, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7605-2 linux-lowlatency, linux-lowlatency-hwe-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- RHSA-2025:20518 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2025:20095 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- USN-7491-1 linux-oem-6.11 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- ELSA-2025-20530 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 18, 2025
- ELSA-2025-20480 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 17, 2025