Cloudanix VulnDB

CVE-2026-99215

None

CVSS

—

EPSS

0.2%

Published

Oct 28, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A Linux bug can make systems crash when power hardware has problems right after being detected.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Use After Free
Remediation
Patch
Effort
Medium
Patch risk
Low

What it actually does

Use-after-free in the Linux kernel power supply core caused by unregistering a supply while external_power_changed or similar callbacks are still executing and accessing driver data.

Why it matters to the business

Kernel crashes and system instability on Linux devices with power management hardware, resulting in unexpected reboots or denial of service during hardware faults or rapid device changes.

How an attack unfolds

Faulty hardware or a malfunctioning bus (such as I2C) immediately after power supply registration causes the core to begin removal while queued callbacks like power_supply_changed_work are still running; the callback then dereferences freed memory, producing a NULL pointer crash.

How to fix it

Apply a kernel patch that introduces a read-write semaphore protecting external_power_changed and power_supply_unregister; rebuild and deploy the updated kernel across affected systems.

How to confirm the fix worked

Inspect kernel source for the added rw_semaphore between callback invocation and unregister paths; reproduce registration/unregistration races under load and confirm absence of NULL dereference oops in power supply workqueues.

Typical attack path

  1. Register a power supply device
  2. Queue external power changed callbacks from other contexts
  3. Trigger hardware bus malfunction to start unregistration
  4. Execute callback after driver data has been freed
  5. Access freed structures leading to kernel oops

How to detect it

Search kernel logs and dmesg for oops traces containing power_supply_changed_work, __power_supply_is_supplied_by, or NULL pointer dereference during power supply workqueue execution.

  • __power_supply_is_supplied_by+0x18/0x100
  • power_supply_changed_work
  • Unable to handle kernel NULL pointer dereference at virtual address 0000000000000005
  • Workqueue: events power_supply_changed_work

What your security team should do

  • Prioritize kernel updates containing the semaphore fix on all Linux systems using power supply drivers
  • Monitor kernel logs for power_supply_changed_work and __power_supply_is_supplied_by oops
  • Test power management hardware removal paths in staging environments before production rollout

The record

In the Linux kernel, the following vulnerability has been resolved: power: supply: core: prevent unregistering a power supply while a callback runs Once a power supply is registered, its callbacks can immediately start firing from other contexts, such as external_power_changed() triggered by the TCPM stack. If a power supply is unregistered while the callback is still running, the driver data can already be freed when the callback tries to access it, leading to a use-after-free. This happens e.g. when the hardware bus carrying the power supply device malfunctions (e.g. I2C is hogged down by another malfunctioning device) immediately after the power supply is registered, and thus the core is still processing the callbacks which were queued up when the driver starts the removal, leading in some cases to a kernel crash, e.g.: [ 11.645942] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000005 [ 11.646751] Mem abort info: [ 11.647006] ESR = 0x0000000096000004 [ 11.647338] EC = 0x25: DABT (current EL), IL = 32 bits [ 11.647806] SET = 0, FnV = 0 [ 11.648077] EA = 0, S1PTW = 0 [ 11.648356] FSC = 0x04: level 0 translation fault [ 11.648785] Data abort info: [ 11.649041] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 11.649524] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 11.649981] GCS = 0, Overlay = 0, DirtyBit = 0 [ 11.650390] [0000000000000005] user address but active_mm is swapper [ 11.650955] Internal error: Oops: 0000000096000004 [#1] SMP [ 11.651460] Modules linked in: [ 11.651742] CPU: 1 UID: 0 PID: 144 Comm: kworker/1:2 Not tainted 7.2.0-rc6-g62a9297af2cd #1 PREEMPT [ 11.652553] Hardware name: Flipper One rev. F0B1C2 (DT) [ 11.653024] Workqueue: events power_supply_changed_work [ 11.653511] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 11.654135] pc : __power_supply_is_supplied_by+0x18/0x100 [ 11.654624] lr : __power_supply_am_i_supplied+0x40/0xb8 [ 11.655098] sp : ffff80008192bb30 [ 11.655399] x29: ffff80008192bb30 x28: 0000000000000000 x27: 0000000000000000 [ 11.656049] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 [ 11.656695] x23: ffff0000c19f4200 x22: ffffdb2232ba4ea8 x21: ffff80008192bc28 [ 11.657344] x20: ffff0000c1eef000 x19: ffff80008192bc18 x18: 00000000a0886e62 [ 11.657991] x17: 000000040044ffff x16: 04500072b5503510 x15: 0000000000000000 [ 11.658639] x14: 0000000000000000 x13: 0000000000000220 x12: 0000000000000000 [ 11.659286] x11: 0000000000000000 x10: ffff0000c1fdb2b0 x9 : ffffdb2232ba5590 [ 11.659934] x8 : 00000000e5b906e6 x7 : ffff0000c2502778 x6 : ffffdb22339793d0 [ 11.660581] x5 : ffff80008192bc18 x4 : ffff0000c19cbca0 x3 : 0000000000000000 [ 11.661228] x2 : ffff0000c1fdaf40 x1 : ffffffffffffffed x0 : ffff0000c1eef000 [ 11.661878] Call trace: [ 11.662103] __power_supply_is_supplied_by+0x18/0x100 (P) [ 11.662596] __power_supply_am_i_supplied+0x40/0xb8 [ 11.663040] psy_for_each_psy_cb+0x20/0x40 [ 11.663416] class_for_each_device+0x110/0x150 [ 11.663825] power_supply_am_i_supplied+0x68/0x100 [ 11.664262] bq257xx_external_power_changed+0x58/0x140 [ 11.664733] __power_supply_changed_work+0x60/0x80 [ 11.665170] psy_for_each_psy_cb+0x20/0x40 [ 11.665545] class_for_each_device+0x110/0x150 [ 11.665953] power_supply_changed_work+0x98/0x1b8 [ 11.666382] process_one_work+0x164/0x4c0 [ 11.666758] worker_thread+0x19c/0x320 [ 11.667104] kthread+0x138/0x150 [ 11.667408] ret_from_fork+0x10/0x20 [ 11.667744] Code: d503233f a9bd7bfd 910003fd a90153f3 (f9400c34) [ 11.668294] ---[ end trace 0000000000000000 ]--- Add a read-write semaphore between external_power_changed() and power_supply_unregister() to prevent the latter from returning (and thus the driver from freeing its data) while the callback is still running.

Affected packages

Ecosystem Package Introduced Fixed