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CVE-2026-89466
power: supply: qcom_battmgr: terminate the strings from firmware
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem drivers/power. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-89466 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 qcom_battmgr_sc8280xp_strcpy() takes a Pascal-style string when the firmware sends one. Otherwise it copies all BATTMGR_STRING_LEN bytes and leaves the destination without a terminator. Those destinations are model_number, serial_number and oem_info, each BATTMGR_STRING_LEN and declared next to each other. They go out to user space as val->strval, which power_supply_format_property() prints with "%s", so a firmware string that fills the whole field makes that read run into the following members. Use strscpy() so the copy always terminates, the way the SM8350 path already does for the same field.
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/power/supply/qcom_battmgr.c
- What this is
- POWER SUPPLY CLASS/SUBSYSTEM and DRIVERSMAINTAINERS section matched on drivers/power/supply/ · linux-pm@vger.kernel.org · Maintained
- Kernel module
- qcom_battmgr
Check it on the machine
grep -wE 'CONFIG_BATTERY_QCOM_BATTMGR|CONFIG_POWER_SUPPLY' /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 qcom_battmgrPrints 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/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-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/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-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_BATTERY_QCOM_BATTMGR, CONFIG_POWER_SUPPLY
- 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
- 7.7 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/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
- unimportantsource
- Subsystem
- drivers/power
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.3 | 6.6.157 | c06028db6208 |
| 6.3 | 6.12.109 | 0e70a9b0d16a |
| 6.3 | 6.18.50 | ee053561e21c |
| 6.3 | 7.2.4 | 6cc6c28c9ab6 |
| 6.3 | 7.3 | ab1112df8f4f |
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 unterminated copies run in qcom_battmgr_sc8280xp_callback() on BATTMGR_BAT_INFO payloads received over on-SoC PMIC GLINK/rpmsg from the Qualcomm ADSP/SOCCP (PMIC_RTR_ADSP_APPS), not from a network protocol, Bluetooth, or a pluggable USB device.
- AC:LAttack complexity, low
- Firmware fully controls the 128-byte model_number, serial_number, and oem_info fields; sending 128 non-NUL bytes (or a first byte that is not a Pascal length) always takes the memcpy() path that omits the terminator, with no race or attacker-uncontrollable layout.
- PR:NPrivileges required, none
- pmic_glink_rpmsg_callback delivers ADSP/SOCCP payloads to qcom_battmgr_callback with no Linux credential or capability check, so compromised PMIC firmware can send BATTMGR_BAT_INFO and NOTIF_BAT_INFO without a host account.
- UI:NUser interaction, none
- Battery-info parsing and power_supply_changed() uevents run from the GLINK response/notification path and from automatic sysfs/uevent reads at boot; no victim must open a file, mount a filesystem, or take any other action.
- S:UScope, unchanged
- The over-read stays in host kernel memory around struct qcom_battmgr in the same OS security authority; this is ordinary kernel disclosure or denial of service, not a VM escape, IOMMU bypass, or sandbox breakout.
- C:HConfidentiality impact, high
- Unterminated model_number, serial_number, and oem_info are printed with %s via world-readable power_supply sysfs and uevents; kernel vsnprintf scans until a NUL, an unbounded out-of-bounds read of adjacent kernel fields and pointers.
- I:NIntegrity impact, none
- qcom_battmgr_sc8280xp_strcpy() copies exactly BATTMGR_STRING_LEN bytes into same-sized destinations; the defect is a missing terminator that causes over-reads, not an out-of-bounds write, use-after-free, or control-flow hijack primitive.
- A:HAvailability impact, high
- Unbounded %s scanning of those unterminated fields can walk past the kmalloc-backed qcom_battmgr object into unmapped pages, causing a kernel oops or panic, and firmware can retrigger the path through GLINK notifications.