CVE-2026-74379

What the bug is

When dev_dax_kmem_probe() partially succeeds (at least one range is mapped) but a subsequent range fails request_mem_region() or add_memory_driver_managed(), the probe silently continues, ultimately returning success, but with the corresponding range resource NULL'ed out. dev_dax_kmem_remove() iterates over all dax_device ranges regardless of if the underlying resource exists. When remove_memory() is called later, it returns 0 because the memory was never added which causes dev_dax_kmem_remove() to incorrectly assume the (nonexistent) resource can be removed and attempts cleanup on a NULL pointer. Fix this by skipping these ranges altogether, noting that these cases are considered success, such that the cleanup is still reached when all actually-added ranges are successfully removed.

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/dax/kmem.c

What this is

DEVICE DIRECT ACCESS (DAX)MAINTAINERS section matched on drivers/dax/ · nvdimm@lists.linux.dev · Supported

Kernel module

kmem

Check it on the machine

grep -wE 'CONFIG_DAX|CONFIG_DEV_DAX_KMEM' /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 kmem

Prints 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/rt/amd64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae, ppc64el/powerpc64le
• trixieMnot built on amd64/rt/amd64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp
• forky, sidMnot built on amd64/rt-amd64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae

M

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

Build switches

CONFIG_DAX, CONFIG_DEV_DAX_KMEM

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

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 11.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/dax

Upstream fixes

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

Introduced	Fixed in	Commit
5.10	5.15.212	ef4fc53898bd
5.10	6.1.178	5d3139abb9d1
5.10	6.6.145	d47b0b8a69a1
5.10	6.12.97	799e54c510a0
5.10	6.18.40	598ed7393a63
5.10	7.1.5	30ea97affbcc
5.10	7.2	8aa442cfce79