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CVE-2026-89472
power: supply: charger-manager: register regulators before exposing sysfs
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem drivers/power. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2026-89472 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 | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| 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
charger_manager_remove() and the err_reg_extcon probe error path free each charger regulator with regulator_put() before tearing down the power_supply sysfs entries (power_supply_unregister()). charger_manager_remove() also calls try_charger_enable(cm, false) after the regulator_put() loop. A concurrent write to a charger's externally_control sysfs attribute that lands between regulator_put() and power_supply_unregister() can run charger_externally_control_store() and call try_charger_enable(), which, when charging is enabled, dereferences the already-freed consumer handle. When charging is enabled, try_charger_enable(cm, false) in .remove() also dereferences the freed handles directly. Both leave use-after-free windows. Symmetrically, probe registers the sysfs entries (power_supply_register) before acquiring the regulators (regulator_get, inside charger_manager_register_extcon), so userspace can reach externally_control before the regulators are available. Split charger_manager_register_extcon() on the sync/async boundary: charger_manager_get_regulators() (regulator_get only, no async producer) now runs before power_supply_register() so sysfs is not live before regulators are available, and charger_manager_register_extcon() keeps only the extcon notifier/work setup, still after power_supply_register() so a power_supply_register() failure cannot reach extcon setup. This keeps the sysfs setup/teardown ordering symmetric without introducing an asynchronous producer on the earlier probe-error path. Move power_supply_unregister() and try_charger_enable(cm, false) ahead of the regulator_put() loop on both teardown paths, and adjust err_reg_extcon (power_supply_unregister() then fall through err_regulator for regulator_put(); get_regulators self-rolls back on its own failure). This does not address the separate extcon-notifier-driven deref of the same handles, which needs its own synchronization design. Found by an in-house static analysis tool.
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/charger-manager.c
- What this is
- POWER SUPPLY CLASS/SUBSYSTEM and DRIVERSMAINTAINERS section matched on drivers/power/supply/ · linux-pm@vger.kernel.org · Maintained
- Kernel module
- none to look for. The file would have gone into charger_manager, and Debian does not compile it into that module, so finding charger_manager in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_CHARGER_MANAGER|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.
Show whether Debian builds this, per release
Debian does not build this code. In 5 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sid, bookworm · linux-6.12n
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_CHARGER_MANAGER, 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
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.16%, higher than 5.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- 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 |
|---|---|---|
| 3.7 | 6.12.109 | af3ce383ba0d |
| 3.7 | 6.18.50 | 86e4fa65368f |
| 3.7 | 7.2.4 | 6d532582ff3c |
| 3.7 | 7.3 | c57cb36f76eb |
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 UAF is reached via local sysfs under /sys/class/power_supply/*/charger.N/{state,externally_control} and via charger_manager_remove()/probe unwind on the charger-manager platform device; this power-supply driver has no network, Bluetooth, or remote packet path into try_charger_enable() or the sysfs handlers.
- AC:LAttack complexity, low
- An attacker can hammer the live sysfs attributes while teardown or probe unwind runs, controlling the sysfs side of the race; charger_manager_remove() also deterministically calls try_charger_enable() on already-freed regulator consumers when charging is enabled, with no attacker-uncontrollable memory layout required.
- PR:LPrivileges required, low
- charger.N/state is mode 0444 and charger_state_show() calls regulator_is_enabled() on the consumer, so an unprivileged local user (including apps on charger-manager phones/embedded devices) can hit the UAF during the teardown or probe window; per driver-removal UAF precedent this is PR:L even though sysfs unbind itself is privileged.
- UI:NUser interaction, none
- The attacker performs their own sysfs reads or writes against the charger-manager power_supply attributes and can race driver unbind or probe; no separate victim action such as mounting a filesystem or confirming a prompt is required.
- S:UScope, unchanged
- The dangling struct regulator is kernel heap used by the same host kernel; this is a standard in-kernel use-after-free/privilege-escalation within one security authority, not a VM escape, IOMMU bypass, or sandbox breakout.
- C:HConfidentiality impact, high
- regulator_put() kfree()s the struct regulator while charger_state_show() and try_charger_enable() still dereference the consumer; this heap UAF lets a reused object be read through regulator_is_enabled() and related helpers, enabling arbitrary kernel information disclosure.
- I:HIntegrity impact, high
- The same dangling consumer is passed to regulator_enable(), regulator_disable(), and regulator_force_disable() from try_charger_enable() and charger_externally_control_store(), so a sprayed heap object can turn the UAF into arbitrary writes and control-flow hijack.
- A:HAvailability impact, high
- Use of the freed or still-NULL regulator consumer oopses or panics the kernel in regulator_is_enabled()/enable()/disable(), and the UAF crashes even when it is not fully converted into a read/write primitive.