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CVE-2026-90027
usb: typec: qcom-pmic-typec: disable cc_debounce_dwork on stop
Published 2026-09-16 (33 days ago) by the Linux kernel CNA. Subsystem drivers/usb. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-90027 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 | 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
cc_debounce_dwork is queued from the set_cc() and start_toggling() callbacks, which run from TCPM's kthread worker. port_stop() returns before tcpm_unregister_port() destroys that worker. Flushing the worker during unregister may therefore run a callback which queues the delayed work after port_stop() has returned. The delayed work can then run after devres has freed pmic_typec_port. Use disable_delayed_work_sync() in port_stop() to cancel a pending instance and prevent the TCPM callbacks from queueing another one. This issue was found by an in-house static analysis tool.
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/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c
- What this is
- QUALCOMM TYPEC PORT MANAGER DRIVERMAINTAINERS section matched on drivers/usb/typec/tcpm/qcom/ · linux-arm-msm@vger.kernel.org · Maintained
- Kernel module
- qcom_pmic_tcpm
Check it on the machine
grep -wE 'CONFIG_OF|CONFIG_PCI|CONFIG_TYPEC|CONFIG_TYPEC_QCOM_PMIC|CONFIG_TYPEC_TCPM|CONFIG_USB|CONFIG_USB_GADGET|CONFIG_USB_PHY|CONFIG_USB_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 qcom_pmic_tcpmPrints 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. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-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/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- bookworm · linux-6.12Mnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switches
- CONFIG_OF, CONFIG_PCI, CONFIG_TYPEC, CONFIG_TYPEC_QCOM_PMIC, CONFIG_TYPEC_TCPM, CONFIG_USB, CONFIG_USB_GADGET, CONFIG_USB_PHY, CONFIG_USB_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
- 2026-09-16 (33 days 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
- unimportantsource
- Subsystem
- drivers/usb
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.5 | 6.12.110 | 4359b5f95c93 |
| 6.5 | 6.18.51 | c614d7c44ca7 |
| 6.5 | 7.2.5 | 1ab669c2b44e |
| 6.5 | 7.3 | 263f7d61a420 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| 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:LAttack vector, local
- The use-after-free is reached on Qualcomm PMIC Type-C platform-driver teardown (sysfs unbind, rmmod, or probe-error unwind after TCPM is registered), not by parsing USB-C/PD traffic from a plugged partner. That matches other USB gadget/UDC and onboard Type-C teardown UAFs scored Local and is higher severity than Physical.
- AC:LAttack complexity, low
- An attacker who initiates remove controls both sides: TCPM set_cc/start_toggling queue the 2ms cc_debounce_dwork, and kthread_destroy_worker() in tcpm_unregister_port() can run those callbacks after port_stop() returns, re-queueing work that then runs after devres frees pmic_typec_port. Use-after-free bugs are AC:L unless the attacker cannot influence the race.
- PR:LPrivileges required, low
- Highest reasonable exposure is a local account on Qualcomm phones, automotive, and embedded boards that manage the Type-C/USB stack, where platform unbind or USB HAL access is often delegated beyond init-namespace root. Uncertain Low versus High, so Low per the overestimate rule.
- UI:NUser interaction, none
- The attacker initiates driver unbind, module unload, or a failing re-probe themselves; no separate victim action such as plugging a USB-C cable, mounting a filesystem, or opening a device node is required.
- S:UScope, unchanged
- The use-after-free corrupts the host kernel pmic_typec_port heap object within the same OS security authority and does not cross a VM, IOMMU, or sandbox boundary.
- C:HConfidentiality impact, high
- qcom_pmic_typec_port_cc_debounce() recovers the freed pmic_typec_port via container_of and reads its spinlock and device pointer; per CNA guidance a use-after-free enables arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- The same delayed work writes debouncing_cc and performs spin_lock/unlock on the freed object, and the pending delayed_work lives inside pmic_typec_port, so heap spray yields an arbitrary write or workqueue function-pointer hijack.
- A:HAvailability impact, high
- Use-after-free of pmic_typec_port from system-wq delayed work after remove causes a kernel oops or panic even without a full exploit, so availability impact is High.