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CVE-2026-64023
gpio: aggregator: fix a potential use-after-free
Published 2026-07-19 (3 months ago) by the Linux kernel CNA. Subsystem drivers/gpio. Debian urgency: unimportant.
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-2026-64023 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 | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
On error we free aggr->lookups->dev_id before removing the entry from the lookup table. If a concurrent thread calls gpiod_find() before we remove the entry, it could iterate over the list and call gpiod_match_lookup_table() which unconditionally dereferences dev_id when calling strcmp(). Reverse the order of cleanup.
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/gpio/gpio-aggregator.c
- What this is
- GPIO AGGREGATORMAINTAINERS section matched on drivers/gpio/gpio-aggregator.c · linux-gpio@vger.kernel.org · Supported
- Kernel module
- none to look for. The file would have gone into gpio_aggregator, and Debian does not compile it into that module, so finding gpio_aggregator in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_GPIOLIB|CONFIG_GPIO_AGGREGATOR' /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 4 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, sidn
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_GPIOLIB, CONFIG_GPIO_AGGREGATOR
- 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
- 2026-07-19 (3 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
- 0.12%, higher than 1.9% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/gpio
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.16 | 6.18.34 | ea28b286649b |
| 6.16 | 7.0.11 | 7ac4183a41ba |
| 6.16 | 7.1 | 30c073cab97a |
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 requires writing to the gpio-aggregator configfs interface at /sys/kernel/config/gpio-aggregator/ (live attribute) or equivalent sysfs driver attributes; there is no network, adjacent, or physical attack path.
- AC:LAttack complexity, low
- The attacker can reliably win the race by concurrently triggering failed aggregator activation (live=1 with probe-forcing config) and GPIO lookup activity (gpiod_find via parallel activations or device probing); both race sides are attacker-controlled.
- PR:LPrivileges required, low
- Default configfs/sysfs access is root-only, but industrial/embedded GPIO-aggregator deployments commonly delegate configfs management to local service accounts; any local user with write access to the gpio-aggregator configfs tree can exploit without full init-namespace root.
- UI:NUser interaction, none
- Exploitation is fully attacker-driven through configfs writes and concurrent threads; no victim interaction is required.
- S:UScope, unchanged
- Impact is confined to kernel memory via the GPIO lookup-table UAF; this is standard local kernel privilege escalation/memory corruption, not a cross-boundary escape (VM, IOMMU, or sandbox).
- C:HConfidentiality impact, high
- The use-after-free dereferences freed dev_id memory in strcmp() during gpiod_match_lookup_table(), enabling arbitrary kernel heap reads and information disclosure.
- I:HIntegrity impact, high
- Use-after-free on a global lookup-table entry can be leveraged with heap grooming for memory corruption and potential arbitrary write or code execution, not merely a bounded modification.
- A:HAvailability impact, high
- Dereferencing freed dev_id memory can cause kernel oops/panic from invalid memory access; UAF bugs inherently threaten system availability even when not fully exploited.