CVE-2026-93256

What the bug is

The arm64 hibernate code manages the exception masking in an unsound way, leading to potential crashes and/or warnings during resume. When a hibernation image is saved in `swsusp_arch_suspend()`, all DAIF exceptions are masked (by virtue of `local_daif_save()`), and the suspended image is saved assuming that all DAIF exceptions will remain masked when the image is restored. When a hibernation image is resumed by `swsusp_arch_resume()`, only interrupts are masked (by virtue of `local_irq_disable()` in `resume_target_kernel()`). When pseudo-NMI is enabled the DAIF.IF bits will be clear, and regardless of pseudo-NMI the DAIF.DA bits will be clear. This means that there are two problems: (1) It is possible to take Debug, SError, or pseudo-NMI exceptions during the resume process. This is unsafe, as during the resume process both the old ane new kernels will tranisently be in an inconsistent state, and swsusp_arch_suspend_exit() won't retain an executable mapping of any exception vectors. Any exception taken here will be fatal and silent. (2) When re-entering the resumed kernel, some DAIF bits will be clear unexpectedly. This permits Debug, SError, or pseudo-NMI exceptions to be taken for a short period while the resumed kernel is not yet in a consistent state. This is detected by CONFIG_ARM64_DEBUG_PRIORITY_MASKING. Avoid these issues by masking all DAIF exceptions during resume.

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.

arch/arm64/kernel/hibernate.c

What this is

ARM64 PORT (AARCH64 ARCHITECTURE)MAINTAINERS section matched on arch/arm64/ · linux-arm-kernel@lists.infradead.org · Maintained

Check it on the machine

grep -w CONFIG_HIBERNATION /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 ppc64el/powerpc64le
• trixie, forky, sidYnot built on ppc64el/powerpc64le, ppc64el/powerpc64le-64k, s390x/s390x
• bookworm · linux-6.12Ynot built on ppc64el/powerpc64le, ppc64el/powerpc64le-64k

Y

built in where it is built at all; some flavours do not build it

Build switch

CONFIG_HIBERNATION

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

2026-09-24 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

arch/arm64

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
4.7	5.10.270	c9c671e9ab87
4.7	5.15.221	099ad3edcef1
4.7	6.1.188	716c41bd4763
4.7	6.6.157	5370853041a3
4.7	6.12.110	290c5b0c9fc0
4.7	6.18.52	012823494e20
4.7	7.2.6	d736ace2c491
4.7	7.3	684bde100117

Debian advisories