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CVE-2026-89626
HID: sensor: custom: Fix field sysfs group cleanup on failure
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem drivers/hid. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-89626 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
hid_sensor_custom_add_attributes() creates one sysfs group for each custom sensor field. If sysfs_create_group() fails after some groups have already been created, the function returns the error without removing the previously created groups. Add a local unwind path to remove the groups that were already created. With enable_sensor exposed only after the field attributes are ready, this path can free sensor_inst->fields without leaving enable_sensor able to access pointers into that array.
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/hid/hid-sensor-custom.c
- What this is
- HID SENSOR HUB DRIVERSMAINTAINERS section matched on drivers/hid/hid-sensor-* · linux-input@vger.kernel.org · Maintained
- Kernel module
- hid_sensor_custom
Check it on the machine
grep -wE 'CONFIG_HID|CONFIG_HID_SENSOR_CUSTOM_SENSOR|CONFIG_HID_SUPPORT' /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 hid_sensor_customPrints 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.
- bookworm, trixieMnot built on arm64/cloud-arm64
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- bookworm · linux-6.12Mnot built on arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_HID, CONFIG_HID_SENSOR_CUSTOM_SENSOR, CONFIG_HID_SUPPORT
- 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
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.35%, higher than 27.6% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/hid
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.1 | 5.10.270 | 416194933af6 |
| 4.1 | 5.15.221 | d0e15091e88d |
| 4.1 | 6.1.188 | 10b05fafff93 |
| 4.1 | 6.6.157 | 2409779f3096 |
| 4.1 | 6.12.109 | 79154fad98ee |
| 4.1 | 6.18.50 | f3f37b937a6e |
| 4.1 | 7.2.4 | d96f8958d446 |
| 4.1 | 7.3 | 3789d0802ddb |
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:AAttack vector, adjacent network
- hid-sensor-hub matches HID_BUS_ANY HID_GROUP_SENSOR_HUB devices and instantiates HID-SENSOR-2000e1/2000e2, so a Bluetooth HID/HoGP peer in radio range can supply a crafted custom-sensor descriptor that probes hid-sensor-custom; USB attach is only a lower-severity physical path.
- AC:LAttack complexity, low
- Duplicate feature/input field group names in the attacker-controlled HID descriptor make sysfs_create_group() fail with -EEXIST after earlier groups are installed, so the missing unwind runs deterministically with no attacker-uncontrollable race or memory layout.
- PR:NPrivileges required, none
- hid_sensor_custom_probe() runs from HID/MFD enumeration when the Bluetooth or USB sensor-hub connects and needs no local account, capability, or userspace authorization.
- UI:NUser interaction, none
- Probe and sysfs group creation run automatically on HID connect; leftover field attributes are then hit by udev and ordinary sysfs reads with no separate victim mount or file-open action.
- S:UScope, unchanged
- The leftover sysfs groups and use-after-free of probe-allocated hid_sensor_custom state remain in the host kernel and do not cross a VM, IOMMU, or sandbox boundary.
- C:HConfidentiality impact, high
- Failed probe leaves field sysfs groups in place while really_probe() device_unbind_cleanup() frees the devm hid_sensor_custom object, so in-progress or later show_value() is a slab use-after-free enabling arbitrary kernel read.
- I:HIntegrity impact, high
- The same dangling sysfs show/store path runs against freed hid_sensor_custom state (fields, mutex, hid-sensor-hub pointers), a heap UAF that can be sprayed for arbitrary write and control-flow hijack.
- A:HAvailability impact, high
- Accessing leftover field attributes after probe failure NULL-dereferences cleared drvdata or uses freed sensor_inst, causing kernel oops/panic; any UAF is High availability impact.