CVE-2026-64297

What the bug is

module_extend_max_pages() calls kvrealloc() internally and returns -ENOMEM on allocation failure. The return value is never checked. If the initial allocation fails, info->pages remains NULL and info->max_pages remains 0. Subsequent calls to module_get_next_page() will attempt to dynamically grow the array by calling module_extend_max_pages(info, 0) since info->used_pages is 0. This results in kvrealloc(NULL, 0) returning ZERO_SIZE_PTR, which is treated as a success, leading to a dereference of ZERO_SIZE_PTR and a kernel oops. Fix: add the missing error check after module_extend_max_pages() and return immediately on failure. This matches the pattern used by every other kvrealloc() caller in the module loading path. [Sami: Corrected the analysis in the commit message.]

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.

kernel/module/decompress.c

What this is

MODULE SUPPORTMAINTAINERS section matched on kernel/module/ · linux-modules@vger.kernel.org · Maintained

Check it on the machine

grep -wE 'CONFIG_MODULES|CONFIG_MODULE_DECOMPRESS' /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 does not build this code in 1 release. It does build it in 4 releases, so the answer depends on which release the machine runs.

• bookwormn
• trixie, forky, sid, bookworm · linux-6.12y

n

not enabled on any flavour - this release does not build the code

y

built into the kernel image on every flavour - only a patch removes it

Build switches

CONFIG_MODULES, CONFIG_MODULE_DECOMPRESS

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

2026-07-25 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.16%, higher than 4.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

kernel/module

Upstream fixes

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

Introduced	Fixed in	Commit
5.17	6.1.178	e7f174715f9f
5.17	6.6.145	afcc0515bbdd
5.17	6.12.96	168072baf9ad
5.17	6.18.39	a82e170637e0
5.17	7.1.4	e7da02659c22
5.17	7.2	786d2d84416a

Debian advisories