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CVE-2026-72314
regulator: core: regulator_lock_two() should test for EDEADLK not EDEADLOCK
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/regulator. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72314 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 | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Compare against -EDEADLK, which is what ww_mutex_lock() actually returns and what every other deadlock check in this file already uses. Function regulator_lock_two() acquires two regulators via regulator_lock_nested() -> ww_mutex_lock(). On contention, ww_mutex_lock() returns -EDEADLK, which is the caller's signal to drop the lock it holds and retry the acquisition in the canonical order. However, regulator_lock_two() tests the return value against -EDEADLOCK rather than -EDEADLK. On most architectures, EDEADLK and EDEADLOCK are the same value, so the comparison happens to be correct and the bug is invisible. But on MIPS, SPARC, and PowerPC, those two errors have different values. The test is wrong: a genuine -EDEADLK backoff no longer matches -EDEADLOCK, so instead of unlocking and retrying, the code falls into WARN_ON(ret) and returns with only one of the two regulators locked. In practice, this is a bug only on MIPS, because the regulator core is not built or used on the other two platforms. In general, EDEADLK is preferred over EDEADLOCK for new code.
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/regulator/core.c
- What this is
- VOLTAGE AND CURRENT REGULATOR FRAMEWORKMAINTAINERS section matched on drivers/regulator/ · linux-kernel@vger.kernel.org · Supported
Check it on the machine
grep -w CONFIG_REGULATOR /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 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.
- bookwormYnot built on amd64/cloud-amd64, arm64/cloud-arm64, ppc64el/powerpc64le
- trixieYnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
- forky, sidYnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- Y
- built in where it is built at all; some flavours do not build it
- Build switch
- CONFIG_REGULATOR
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
- 2026-08-15 (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 6.7% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/regulator
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.10.180 | 5.10.261 | dc804f390fdd |
| 5.15.111 | 5.15.212 | 8e39aa63798e |
| 6.1.28 | 6.1.178 | 0c305eac4047 |
| 6.4 | 6.6.145 | 29a7953e9ade |
| 6.4 | 6.12.97 | e2063307ea3b |
| 6.4 | 6.18.40 | 346e2d666a29 |
| 6.4 | 7.1.5 | 153d1b8b5bc3 |
| 6.4 | 7.2 | d38f8bd771c4 |
| 5.4.243 | 0 | 0 |
| 6.2.15 | 0 | 0 |
| 6.3.2 | 0 | 0 |
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 bug is in drivers/regulator/core.c and is reached only through local kernel paths (regulator_register(), regulator_get()/devm_regulator_get(), and regulator_bus_probe()) during driver probing and supply resolution, not via any network protocol or remote packet handler.
- AC:LAttack complexity, low
- Triggering -EDEADLK requires concurrent regulator_resolve_supply() on interdependent regulators; an attacker who can influence driver probing (e.g., parallel module loads or concurrent async platform probe work) controls both sides of the ww_mutex contention and can reliably force the mis-handled backoff path on MIPS.
- PR:LPrivileges required, low
- Deliberate exploitation needs only basic local access on MIPS embedded/IoT systems where concurrent async regulator supply resolution during driver probe is common; hardened systems may require module-load privileges, but user namespaces do not gate this subsystem and misconfigured deployments widen reach.
- UI:NUser interaction, none
- No victim interaction is required once the attacker can trigger concurrent regulator supply resolution; exploitation is driven entirely by attacker-controlled driver probing/concurrency rather than requiring a user to mount, open, or configure anything.
- S:UScope, unchanged
- Impact is confined to kernel memory/locking integrity and local privilege boundaries (improperly locked regulator_dev state); it does not cross VM, container, or IOMMU security boundaries into a separate authority.
- C:HConfidentiality impact, high
- Failing to acquire both regulator mutexes before set_supply()/create_regulator() permits unsynchronized list_add() to consumer_list and open_count updates, creating exploitable races that can yield kernel memory disclosure primitives alongside corruption.
- I:HIntegrity impact, high
- Operating on regulator_dev supply pointers, consumer_list, and open_count without holding both ww_mutex locks enables heap/list corruption and use-after-free style races that are reasonably leveragable for arbitrary kernel write or control-flow hijack on MIPS.
- A:HAvailability impact, high
- The broken EDEADLK handling leaves regulators in an inconsistent partially-locked state, emitting WARN_ON and risking kernel deadlocks, hangs, or oops during concurrent supply resolution on MIPS systems where EDEADLK and EDEADLOCK differ.