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.
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.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2025-9419 | 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. |
Ubuntu USN |
USN-7491-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-7605-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7605-2 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7628-1 | Linux kernel (Azure) vulnerabilities |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 31 Oct 2025 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Wed, 02 Apr 2025 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Tue, 01 Apr 2025 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | acpi: typec: ucsi: Introduce a ->poll_cci method | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:23:51.470Z
Reserved: 2024-12-29T08:45:45.785Z
Link: CVE-2025-21902
No data.
Status : Analyzed
Published: 2025-04-01T16:15:20.650
Modified: 2025-10-31T18:51:38.927
Link: CVE-2025-21902
OpenCVE Enrichment
No data.
EUVD
Ubuntu USN