CVE-2026-81015

platform/x86/amd/pmc: Fix LPS0 and debugfs leaks when STB init fails

Published Sep 11, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

platform/x86/amd/pmc: Fix LPS0 and debugfs leaks when STB init fails

amd_pmc_probe() registers the LPS0 s2idle handler with
acpi_register_lps0_dev() and creates the driver's debugfs directory before
calling amd_stb_s2d_init(), which is the last step in probe that can fail.

When amd_stb_s2d_init() fails (for example the S2D telemetry region cannot
be ioremapped on a long-running system, or the SMU rejects the S2D setup)
the error path only calls pci_dev_put() and returns. This leaves
amd_pmc_s2idle_dev_ops on the global lps0_s2idle_devops_head list and leaks
the debugfs directory, while the devm-managed resources backing the handler
are torn down.

Reloading the module then walks the corrupted list in
acpi_register_lps0_dev() and hits:

list_add corruption. next->prev should be prev, but was NULL.
kernel BUG at lib/list_debug.c:29!
acpi_register_lps0_dev+0x44/0x80
amd_pmc_probe+0x224/0x380 [amd_pmc]
platform_probe+0x67/0x90

Even without a reload, the stale registration means the next s2idle
transition calls into torn-down driver state.

Unwind the debugfs directory and the LPS0 registration on the
amd_stb_s2d_init() error path. acpi_unregister_lps0_dev() is safe to call
unconditionally here: it is guarded on the same conditions as
acpi_register_lps0_dev(), which is exactly what amd_pmc_remove() already
relies on.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses CWE-459
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd/pmc: Fix LPS0 and debugfs leaks when STB init fails amd_pmc_probe() registers the LPS0 s2idle handler with acpi_register_lps0_dev() and creates the driver's debugfs directory before calling amd_stb_s2d_init(), which is the last step in probe that can fail. When amd_stb_s2d_init() fails (for example the S2D telemetry region cannot be ioremapped on a long-running system, or the SMU rejects the S2D setup) the error path only calls pci_dev_put() and returns. This leaves amd_pmc_s2idle_dev_ops on the global lps0_s2idle_devops_head list and leaks the debugfs directory, while the devm-managed resources backing the handler are torn down. Reloading the module then walks the corrupted list in acpi_register_lps0_dev() and hits: list_add corruption. next->prev should be prev, but was NULL. kernel BUG at lib/list_debug.c:29! acpi_register_lps0_dev+0x44/0x80 amd_pmc_probe+0x224/0x380 [amd_pmc] platform_probe+0x67/0x90 Even without a reload, the stale registration means the next s2idle transition calls into torn-down driver state. Unwind the debugfs directory and the LPS0 registration on the amd_stb_s2d_init() error path. acpi_unregister_lps0_dev() is safe to call unconditionally here: it is guarded on the same conditions as acpi_register_lps0_dev(), which is exactly what amd_pmc_remove() already relies on.
Title platform/x86/amd/pmc: Fix LPS0 and debugfs leaks when STB init fails
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 19, 2026, 8:46 AM
Reserved
Aug 26, 2026, 2:34 PM
Status
Received
Published
Sep 11, 2026, 8:19 PM
Modified
Oct 19, 2026, 9:17 AM
Severity
Moderate
Public date
Sep 11, 2026, 7:43 PM