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CVE-2026-72143
platform/x86: ISST: Restore SST-PP control to all domains
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/platform. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-72143 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The SST-PP control offset is only restored to power domain 0 after resume. During suspend, control values are read and stored for all power domains. Use pd_info->sst_base instead of power_domain_info->sst_base, which only points to power domain 0 base address.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
- What this is
- INTEL SPEED SELECT TECHNOLOGYMAINTAINERS section matched on drivers/platform/x86/intel/speed_select_if/ · platform-driver-x86@vger.kernel.org · Maintained
- Kernel module
- isst_tpmi_core
Check it on the machine
grep -wE 'CONFIG_INTEL_SPEED_SELECT_INTERFACE|CONFIG_INTEL_SPEED_SELECT_TPMI|CONFIG_X86' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w isst_tpmi_corePrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switches
- CONFIG_INTEL_SPEED_SELECT_INTERFACE, CONFIG_INTEL_SPEED_SELECT_TPMI, CONFIG_X86
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 7.1 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.8% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/platform
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.18.16 | 6.18.40 | cea03d67db3a |
| 7.0 | 7.1.5 | 2a42f651cce9 |
| 7.0 | 7.2 | 2565a28cdcdc |
| 6.19.6 | 0 | 0 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The flawed writeq runs only in the ISST TPMI driver PM resume callback (intel_sst_resume -> tpmi_sst_dev_resume) after a local suspend-to-RAM cycle, not from any network packet handler or remote service.
- AC:LAttack complexity, low
- Once a multi-domain SST-TPMI system completes S3 suspend, resume deterministically executes the wrong MMIO restore for every power domain above zero with no races or attacker-dependent timing.
- PR:LPrivileges required, low
- Reaching the buggy resume handler requires only initiating a system suspend (e.g., writing mem to /sys/power/state, which lacks a CAP_SYS_ADMIN check, or polkit-permitted local suspend); user namespaces cannot grant ISST ioctl writes but can still allow this PM path.
- UI:NUser interaction, none
- Exploitation does not require a victim to open files, mount filesystems, or take any other interactive action beyond the attacker (or system policy) triggering suspend and automatic resume.
- S:UScope, unchanged
- Impact is confined to corrupting SST-PP hardware configuration and host stability on the same machine; it does not cross a VM, container, or IOMMU security boundary to another authority.
- C:NConfidentiality impact, none
- The bug performs MMIO writeq operations to hardware registers only; it does not read kernel memory, leak pointers, or expose data to userspace.
- I:HIntegrity impact, high
- Each incorrect resume writes a full 64-bit SST-PP control value to the wrong hardware MMIO address, corrupting platform power/performance configuration; values can be attacker-influenced via prior CAP_SYS_ADMIN ISST perf-level changes before suspend.
- A:HAvailability impact, high
- Misdirected MMIO writes can panic or hang the host, and unrestored or corrupted SST-PP settings on additional power domains can destabilize multi-die Xeon systems after every affected resume cycle.