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CVE-2026-97451
ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op)
Published 2026-09-24 (24 days ago) by the Linux kernel CNA. Subsystem drivers/acpi. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-97451 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 | fixedDLA-4841-1 · 2026-10-17 · text | 6.1.190-1 | Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts. |
| 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
Add overflow check for Index + Length to prevent integer overflow when calculating the truncation length. This prevents negative size parameter being passed to memcpy().
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/acpi/acpica/exoparg3.c
- What this is
- ACPI COMPONENT ARCHITECTURE (ACPICA)MAINTAINERS section matched on drivers/acpi/acpica/ · linux-acpi@vger.kernel.org · Supported
Check it on the machine
grep -w CONFIG_ACPI /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.
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.
- bookwormYnot built on armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
- trixieYnot built on armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- forky, sidYnot built on armhf/armmp, armhf/armmp-lpae, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- bookworm · linux-6.12Ynot built on armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- Y
- built in where it is built at all; some flavours do not build it
- Build switch
- CONFIG_ACPI
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
- 2026-09-24 (24 days ago)source
- CVSS
- 8.4 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.14%, higher than 3.1% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/acpi
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.12 | 5.10.271 | 6da963ed4c3d |
| 2.6.12 | 5.15.222 | e539003886b3 |
| 2.6.12 | 6.1.189 | 9010ad440f97 |
| 2.6.12 | 6.6.158 | 4532c9cf006b |
| 2.6.12 | 6.12.111 | d0d89f2e16a8 |
| 2.6.12 | 6.18.53 | b96401812cbf |
| 2.6.12 | 7.2 | 0e2021f49e64 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4841-1 | 2026-10-17 | bookworm 6.1.190-1 | tracker |
| 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 wrapping Index and Length are AML integer operands of Mid() in acpi_ex_opcode_3A_1T_1R(), taken from the local DSDT/SSDT. The path is acpi_bus_init() → acpi_load_tables() → acpi_tb_load_namespace() → acpi_ns_load_table() → acpi_ns_execute_table() → acpi_ds_exec_end_op(); no network protocol carries those integers.
- AC:LAttack complexity, low
- A Mid() whose Index is in [1, Source.length) and Length is Ones (UINT64_MAX) makes (index+length) wrap so truncation is skipped; the STRING path then kzalloc(length+1)==kzalloc(0) and memcpy(..., length) on every acpi_ns_execute_table() of that table. The table author sets those operands; no race.
- PR:NPrivileges required, none
- acpi_bus_init() calls acpi_load_tables(), which runs module-level Mid() in acpi_ns_execute_table() with no capable() or uid check. A compromised DSDT/SSDT is enough; no Linux account, user namespace, or /sys/kernel/config/acpi/table write is required.
- UI:NUser interaction, none
- acpi_ns_execute_table() evaluates definition-block AML, including a module-level Mid(), automatically during acpi_load_tables() at boot. No mount, file-open, or other victim action is required at trigger time.
- S:UScope, unchanged
- The overflowing memcpy in acpi_ex_opcode_3A_1T_1R() corrupts the host kernel heap around the Mid() result object from ACPI_ALLOCATE_ZEROED; it does not cross a KVM/Xen, IOMMU, or sandbox boundary.
- C:HConfidentiality impact, high
- After the wrap, memcpy() in acpi_ex_opcode_3A_1T_1R() reads the untruncated length (UINT64_MAX) bytes from operand[0]->string.pointer+index, whose object is only operand[0]->string.length (u32) bytes, an unbounded kernel heap over-read rather than a few-byte leak.
- I:HIntegrity impact, high
- On ACPI_TYPE_STRING, ACPI_ALLOCATE_ZEROED(length+1) wraps to a 0-size allocation when length is UINT64_MAX, then memcpy writes that same untruncated length into it—an out-of-bounds write/heap overflow exploitable for control-flow hijack.
- A:HAvailability impact, high
- memcpy of the untruncated length into the wrapped 0-size STRING buffer in acpi_ex_opcode_3A_1T_1R() oopses or panics the kernel during acpi_ns_execute_table() or a later Mid() method evaluation.