CVE-2024-38630

What the bug is

When the cpu5wdt module is removing, the origin code uses del_timer() to de-activate the timer. If the timer handler is running, del_timer() could not stop it and will return directly. If the port region is released by release_region() and then the timer handler cpu5wdt_trigger() calls outb() to write into the region that is released, the use-after-free bug will happen. Change del_timer() to timer_shutdown_sync() in order that the timer handler could be finished before the port region is released.

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/watchdog/cpu5wdt.c

What this is

WATCHDOG DEVICE DRIVERSMAINTAINERS section matched on drivers/watchdog/ · linux-watchdog@vger.kernel.org · Maintained

Kernel module

cpu5wdt

Check it on the machine

grep -wE 'CONFIG_CPU5_WDT|CONFIG_WATCHDOG' /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 cpu5wdt

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. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookwormMnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
• trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• forky, sid?

M

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

?

not established - no Makefile entry for the affected file

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 switches

CONFIG_CPU5_WDT, CONFIG_WATCHDOG

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

2024-06-21 (2 years ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.25%, higher than 15.3% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/watchdog

Upstream fixes

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

Introduced	Fixed in	Commit
2.6.12	6.6.33	9b1c063ffc07
2.6.12	6.9.4	f19686d61650
2.6.12	6.10	573601521277