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CVE-2026-80559
Input: sur40 - fix input device registration ordering
Published 2026-08-26 (2 months ago) by the Linux kernel CNA. Subsystem drivers/input. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-80559 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-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.105-1 | Update the kernel and reboot. Fixed in 6.12.105-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.10-1 | Update the kernel and reboot. Fixed in 7.1.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.10-1 | Update the kernel and reboot. Fixed in 7.1.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4788-1 · 2026-09-19 · text | 6.12.107-1~deb12u1 | Update the kernel and reboot. DLA-4788-1 shipped the fix on 2026-09-19, in 6.12.107-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
In sur40_probe(), input_register_device() was previously called early before the V4L2 video device and vb2_queue components were fully initialized. If userspace opened the input device immediately upon registration, sur40_open() would trigger and start the sur40_poll() worker thread. This worker thread invokes sur40_process_video() and accesses the uninitialized vb2_queue structure, leading to a data race and potential system crash. Furthermore, if V4L2 or video registration failed after input_register_device() succeeded, the error path fell through to calling input_free_device() on a successfully registered device instead of input_unregister_device(), corrupting input core state. Move input_register_device() to the very end of sur40_probe(). This ensures the V4L2 and video queue structures are fully initialized before polling can start, and naturally resolves the error path bug since input_free_device() is now only called when input registration has not yet occurred. To maintain strict LIFO (Last-In, First-Out) teardown ordering, also move input_unregister_device() to the very beginning of sur40_disconnect(). This guarantees that the input polling worker thread is stopped before V4L2 video components or control handlers are unregistered.
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/input/touchscreen/sur40.c
- What this is
- INPUT (KEYBOARD, MOUSE, JOYSTICK, TOUCHSCREEN) DRIVERSMAINTAINERS section matched on drivers/input/ · linux-input@vger.kernel.org · Maintained
- Kernel module
- sur40
Check it on the machine
grep -wE 'CONFIG_INPUT|CONFIG_INPUT_TOUCHSCREEN|CONFIG_TOUCHSCREEN_SUR40' /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 sur40Prints 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.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, loong64/loong64, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_INPUT, CONFIG_INPUT_TOUCHSCREEN, CONFIG_TOUCHSCREEN_SUR40
- 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
- 2026-08-26 (2 months 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
- 0.18%, higher than 6.6% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/input
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.1 | 5.10.266 | cd4ecce2fd87 |
| 4.1 | 5.15.217 | dab741c9da72 |
| 4.1 | 6.1.184 | 764b507be7b5 |
| 4.1 | 6.6.153 | 3e8ed76a4f35 |
| 4.1 | 6.12.105 | 83aa12f9f246 |
| 4.1 | 6.18.46 | 5c1c5227c93f |
| 4.1 | 7.1.10 | beb9b0bd6e6e |
| 4.1 | 7.2 | 9da976eb649c |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4788-1 | 2026-09-19 | bookworm 6.12.107-1~deb12u1 | tracker |
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | 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
- Exploitation is via open() on /dev/input/eventX (evdev -> input_open_device -> sur40_open -> sur40_poll -> sur40_process_video) racing sur40_probe() before vb2_queue_init(); on permanently installed PixelSense/SUR40 kiosk tables no physical USB access is needed at attack time.
- AC:LAttack complexity, low
- The attacker controls both sides of the race by monitoring udev/inotify for the new input node and immediately opening it during USB hotplug or reboot probe; polling starts synchronously in input_dev_poller_start, making the uninitialized vb2_queue access reliably triggerable without uncontrollable kernel preconditions.
- PR:LPrivileges required, low
- Triggering sur40_open requires only local userspace access to the evdev node (typically membership in the input group or equivalent kiosk-app privileges opening /dev/input/event*), not real root in the init namespace; user namespaces cannot substitute for this device access.
- UI:NUser interaction, none
- No victim interaction is required beyond the attacker's own actions; they can open the input device themselves (or rely on an auto-opening compositor during reconnect) and time the race during probe without needing another user to touch the screen or perform any action.
- S:UScope, unchanged
- Impact is confined to kernel memory corruption and crashes within the host input/USB driver context on the same system; it does not cross VM, container, or IOMMU security boundaries despite potential local privilege escalation as a follow-on.
- C:HConfidentiality impact, high
- Concurrent access to a partially initialized vb2_queue is a kernel data race that can read uninitialized queue state, and the probe error path calls input_free_device() on a registered device, corrupting input-core linked lists—both are memory-corruption primitives leverageable for kernel information disclosure.
- I:HIntegrity impact, high
- The input_free_device() misuse corrupts global input-core list state (definite kernel structure corruption), and racing poll against vb2_queue_init can invoke vb2_buffer_done and list operations on uninitialized queue internals, enabling exploitable heap/control-structure writes.
- A:HAvailability impact, high
- The fix commit explicitly cites a data race on the uninitialized vb2_queue leading to system crash; corrupting input-core registration state or racing teardown during USB disconnect can cause kernel oops/panic and deny service on interactive SUR40/PixelSense deployments.