CVE-2026-68165

What the bug is

DAMON core logic assumes zero length regions don't exist. However, a few DAMON API callers including DAMON_SYSFS, DAMON_RECLAIM and DAMON_LRU_SORT allow users to set empty monitoring target regions. This could result in WARN_ONCE() on CONFIG_DAMON_DEBUG_SANITY enabled kernel, and divide-by-zero from damon_merge_two_regions(). For example, the WANR_ONCE() can be triggered like below. # grep DAMON_DEBUG_SANITY /boot/config-$(uname -r) # CONFIG_DAMON_DEBUG_SANITY=y # damo start # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/0/targets/0/regions/0/start # echo 0 > contexts/0/targets/0/regions/0/end # echo commit > state # dmesg [....] [ 73.705780] ------------[ cut here ]------------ [ 73.707552] start 0 >= end 0 [ 73.708452] WARNING: mm/damon/core.c:359 at damon_new_region+0x6e/0x80, CPU#1: kdamond.0/758 [...] All DAMON API callers eventually use damon_set_regions() to setup the regions. Add the validation logic in the function.

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.

mm/damon/core.c

What this is

DAMONMAINTAINERS section matched on mm/damon/ · damon@lists.linux.dev · Maintained

Check it on the machine

grep -w CONFIG_DAMON /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 switch

CONFIG_DAMON

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

2026-08-10 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

mm/damon

Upstream fixes

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

Introduced	Fixed in	Commit
5.16	6.1.183	71cf8a3ee1c1
5.16	6.6.148	b585facbafbb
5.16	6.12.101	c927b73a5694
5.16	6.18.42	4b6f1d6d5d07
5.16	7.1.6	43aaddd0fa92
5.16	7.2	1292c0ecb1ca

Debian advisories