CVE-2025-68376

What the bug is

When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed and enabled again, currently sysfs_buf will point to the newly allocated memory(buf_new) and free the old memory(buf_old). But the etr_buf that is being used by the ETR remains pointed to buf_old, not updated to buf_new. In this case, it will result in a memory use-after-free issue. Fix this by checking ETR's mode before updating and releasing buf_old, if the mode is CS_MODE_SYSFS, then skip updating and releasing it.

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/hwtracing/coresight/coresight-tmc-etr.c

What this is

ARM/CORESIGHT FRAMEWORK AND DRIVERSMAINTAINERS section matched on drivers/hwtracing/coresight/* · coresight@lists.linaro.org · Maintained

Kernel module

coresight_tmc

Check it on the machine

grep -w CONFIG_CORESIGHT_LINK_AND_SINK_TMC /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 coresight_tmc

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 does not build this code in 1 release. It does build it in 3 releases, so the answer depends on which release the machine runs.

• bookwormn
• trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, armel/rpi, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x

n

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

M

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

Build switch

CONFIG_CORESIGHT_LINK_AND_SINK_TMC

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

2025-12-24 (10 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.19%, higher than 7.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/hwtracing

Upstream fixes

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

Introduced	Fixed in	Commit
6.6	6.17.13	70acbc9c7768
6.6	6.18.2	cda077a19f5c
6.6	6.19	35501ac3c7d4
6.5.8	0	0