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CVE-2026-81011
platform/x86: hp-bioscfg: pass validated element count to package parsers
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem drivers/platform. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-81011 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 | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The per-type package parsers are handed the wrong element count. hp_init_bios_package_attribute() validates obj->package.count and then calls one of the five hp_populate_*_package_data() wrappers (string, integer, enumeration, ordered list, password). Each wrapper forwards a count to its hp_populate_*_elements_from_package() parser, but instead of forwarding the validated obj->package.count it derives the count from elements[0]. elements[0] is the NAME field and is always an ACPI_TYPE_STRING, so reading ->package.count from it in fact reads ->string.length through the union acpi_object. The parsers thus bound themselves against the length of the name string rather than against the real number of elements in the package. This is safe today because hp_init_bios_package_attribute() refuses any package that has fewer than the type's element count, so a parser only ever runs on a full package and never reads past it regardless of the bogus bound. An upcoming change relaxes that check to accept shorter packages. Once a parser can receive fewer elements than its per-type count, a bound taken from the name length no longer reflects the array size, and the "elem < count" loop conditions and "elem + n >= count" sub-loop guards read past the end of elements[] - an out-of-bounds heap read. Forward the validated obj->package.count to every *_package_data() wrapper so the parsers bound themselves against the real package size. This does not change behaviour for the packages that enumerate correctly today and is a prerequisite for accepting shorter packages safely.
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/hp/hp-bioscfg/bioscfg.c
drivers/platform/x86/hp/hp-bioscfg/bioscfg.h
drivers/platform/x86/hp/hp-bioscfg/enum-attributes.c
drivers/platform/x86/hp/hp-bioscfg/int-attributes.c
drivers/platform/x86/hp/hp-bioscfg/order-list-attributes.c
drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
drivers/platform/x86/hp/hp-bioscfg/string-attributes.c
- What this is
- HP BIOSCFG DRIVERMAINTAINERS section matched on drivers/platform/x86/hp/hp-bioscfg/ · platform-driver-x86@vger.kernel.org · Maintained
- Kernel module
- hp_bioscfg
Check it on the machine
grep -wE 'CONFIG_HP_BIOSCFG|CONFIG_X86|CONFIG_X86_PLATFORM_DRIVERS_HP' /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 hp_bioscfgPrints 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
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- ?
- 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_HP_BIOSCFG, CONFIG_X86, CONFIG_X86_PLATFORM_DRIVERS_HP
- 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
- 2026-09-11 (37 days ago)source
- CVSS
- 7.1 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.12%, higher than 2.0% 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 |
|---|---|---|
| 6.6 | 6.6.157 | 467e53f231f7 |
| 6.6 | 6.12.109 | 436017808c7c |
| 6.6 | 6.18.50 | a38127df99ae |
| 6.6 | 7.2.4 | 400cbc3ccc88 |
| 6.6 | 7.3 | e0ddfd77c0c3 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
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 hp-bioscfg package parsers run during local driver initialization on ACPI/WMI objects fetched by wmi_query_block(); there is no network, adjacent-radio, or USB/peripheral path into this code.
- AC:LAttack complexity, low
- A NAME whose string.length exceeds the real package.count makes the nested elem+n bounds and outer elem<count loops walk past elements[] whenever a multi-element field such as PREREQUISITES is present; a crafted or shortened firmware package triggers that over-read deterministically, with no race or attacker-uncontrollable layout.
- PR:LPrivileges required, low
- hp-bioscfg autoloads on HP WMI GUIDs, and parsed fields are copied into world-readable sysfs attributes under firmware-attributes/hp-bioscfg; an ordinary local user can read that metadata, and no capability or user-namespace gate protects the path.
- UI:NUser interaction, none
- Parsing occurs in hp_init()/hp_init_bios_attributes() on module load or built-in init; exploitation does not require a victim to open a file, mount a filesystem, or take any other action.
- S:UScope, unchanged
- The out-of-bounds heap read, any resulting kernel-memory disclosure, and any oops remain inside the same kernel security authority; this is not a VM, IOMMU, or sandbox escape.
- C:HConfidentiality impact, high
- Out-of-bounds union acpi_object slots are treated as STRING objects, so hp_convert_hexstr_to_str() follows an OOB pointer and length and copies the result into sysfs-visible buffers, yielding an unbounded kernel read rather than a few-byte leak.
- I:NIntegrity impact, none
- The flaw is an out-of-bounds read; parsed values are stored through bounded strscpy and scalar assignment into fixed-size driver fields, with no OOB write or control-flow hijack primitive.
- A:HAvailability impact, high
- An out-of-bounds descriptor with a bogus string.pointer is dereferenced by hp_convert_hexstr_to_str(), which causes a kernel oops or panic during driver initialization.