CVE-2026-93240

What the bug is

The v1 soft limit has been deprecated since v6.12 and nobody has reported depending on it. Start the removal by decoupling the interface from the implementation: keep memory.soft_limit_in_bytes, but ignore writes to it and always report the maximum value on read similar to what memory.kmem.limit_in_bytes already does. Writes are still parsed, so malformed input keeps returning -EINVAL. The knob now also behaves the same everywhere: it used to return -EOPNOTSUPP on PREEMPT_RT, where soft limit reclaim has always been disabled. This also fixes the syzbot report linked below. Soft limit reclaim is the only caller that runs shrink_lruvec() from kswapd against a specific memcg, so it is the only way to reach lru_gen_shrink_lruvec() and in turn set_mm_walk(), which warns when called from kswapd.

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.

Documentation/admin-guide/cgroup-v1/memory.rst
mm/memcontrol-v1.c

What this is

CONTROL GROUP (CGROUP)MAINTAINERS section matched on Documentation/admin-guide/cgroup-v1/ · cgroups@vger.kernel.org · Maintained

Check it on the machine

grep -w CONFIG_MEMCG_V1 /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 4 releases. The build rule could not be established for 1 release, so nothing is claimed about those.

• bookworm?
• trixie, forky, sid, bookworm · linux-6.12n

?

not established - no Makefile entry for the affected file

n

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

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switch

CONFIG_MEMCG_V1

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

0.22%, higher than 11.4% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

Documentation/admin-guide

Upstream fixes

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

Introduced	Fixed in	Commit
6.3	6.12.110	72fb67f6e0e5
6.3	6.18.51	0a90e268cce7
6.3	7.2.5	5ec8f629a300
6.3	7.3	a3417097fb10

Debian advisories