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CVE-2026-80680
i2c: amd-mp2: Unregister callback on adapter add failure
Published 2026-08-28 (2 months ago) by the Linux kernel CNA. Subsystem drivers/i2c. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-80680 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 | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.8-1 | Update the kernel and reboot. Fixed in 7.1.8-1. 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
amd_mp2_register_cb() stores the platform I2C context in the MP2 PCI driver's callback table before the adapter is registered. If i2c_add_adapter() fails, probe returns and devres frees the context, but the PCI driver can still dereference the stale pointer from its IRQ and system-sleep callbacks. Unregister the callback before returning the adapter registration error.
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/i2c/busses/i2c-amd-mp2-plat.c
- What this is
- AMD MP2 I2C DRIVERMAINTAINERS section matched on drivers/i2c/busses/i2c-amd-mp2* · linux-i2c@vger.kernel.org · Maintained
- Kernel module
- i2c_amd_mp2_plat
Check it on the machine
grep -w CONFIG_I2C_AMD_MP2 /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 i2c_amd_mp2_platPrints 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/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
- trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_I2C_AMD_MP2
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
- 2026-08-28 (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/i2c
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.2 | 5.10.265 | 9142a3dcff0d |
| 5.2 | 5.15.216 | 2f7789b3a962 |
| 5.2 | 6.1.183 | 4786d4d70dcd |
| 5.2 | 6.6.151 | b7c2c5c88687 |
| 5.2 | 6.12.103 | cf107c5983dc |
| 5.2 | 6.18.44 | 1883a09a37fe |
| 5.2 | 7.1.8 | 8bf719659406 |
| 5.2 | 7.2 | 82048795242f |
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
- The flaw is in AMD MP2 platform-driver probe teardown and PCI IRQ/system-sleep callbacks, reachable only via local suspend/resume or MP2 hardware interrupts on affected Ryzen laptops; there is no network, Bluetooth, or userspace I2C ioctl path to the stale callback table.
- AC:LAttack complexity, low
- Once i2c_add_adapter() fails the dangling busses[] pointer is deterministic; an attacker can force that registration failure with memory pressure or driver rebind on modular builds, then reliably trigger the UAF through system suspend or MP2 IRQ without uncontrollable races.
- PR:LPrivileges required, low
- After the flawed probe error path leaves the stale callback registered, local users can invoke system suspend via logind/systemctl without init-namespace root, and MP2 IRQs can fire from the already-enabled bus; per CNA guidance Low is used when probe/bind privilege gating is ambiguous.
- UI:NUser interaction, none
- Exploitation requires no separate victim action; the attacker triggers suspend themselves or relies on automatic MP2 hardware interrupts from an enabled bus, without needing another user to mount filesystems or open files.
- S:UScope, unchanged
- Impact is host-kernel heap corruption and privilege escalation from stale callback dereference; it does not cross VM, IOMMU, or sandbox security boundaries.
- C:HConfidentiality impact, high
- The IRQ handler writes into freed amd_i2c_common memory and invokes cmd_completion from the stale object; this UAF provides attacker-influenced heap reuse and arbitrary kernel read primitives per kernel CNA UAF guidance.
- I:HIntegrity impact, high
- Suspend/resume and IRQ paths call function pointers through the freed amd_i2c_common structure, enabling control-flow hijack and heap corruption consistent with exploitable UAF write primitives.
- A:HAvailability impact, high
- Stale callback dereference in IRQ or system-sleep paths causes kernel oops/panic and loss of availability; UAF heap corruption can also hang or crash affected AMD MP2 systems on every suspend or interrupt.