CVE-2026-72047

What the bug is

ca8210_test_int_driver_write() and ca8210_test_int_user_read() exchange a kmalloc'd buffer pointer through a struct kfifo, but pass a literal '4' as the byte count to kfifo_in()/kfifo_out(). This is correct on 32-bit (pointer = 4 bytes), but on 64-bit only the low 4 bytes of the 8-byte pointer are written into the FIFO. The reader then reads back 4 bytes into an 8-byte local pointer variable, leaving the upper 4 bytes uninitialized stack data. The first dereference of the reconstructed pointer (fifo_buffer[1]) accesses an arbitrary kernel address and generally results in an oops. Use sizeof(fifo_buffer) so the byte count matches pointer width on every architecture. The driver has no architecture restriction in Kconfig, so any 64-bit build with CONFIG_IEEE802154_CA8210_DEBUGFS=y is exposed. Issue has been latent since the driver was added in 2017 because it is most commonly deployed on 32-bit MCUs. Found via a custom Coccinelle semantic patch hunting for short-byte kfifo I/O on byte-mode kfifos used to shuttle pointers.

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/net/ieee802154/ca8210.c

What this is

CA8210 IEEE-802.15.4 RADIO DRIVERMAINTAINERS section matched on drivers/net/ieee802154/ca8210.c · linux-wpan@vger.kernel.org · Orphan

Kernel module

none to look for. The file would have gone into ca8210, and Debian does not compile it into that module, so finding ca8210 in lsmod would say nothing about this CVE.

Check it on the machine

grep -wE 'CONFIG_IEEE802154|CONFIG_IEEE802154_CA8210' /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 below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sidn

n

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

Build switches

CONFIG_IEEE802154, CONFIG_IEEE802154_CA8210

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

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.22%, higher than 11.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/net

Upstream fixes

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

Introduced	Fixed in	Commit
4.12	5.10.261	2c1664ccfae6
4.12	5.15.212	093aacb0c56d
4.12	6.1.178	87dab14a4f68
4.12	6.6.145	1fe2643d0b24
4.12	6.12.97	65dc342274a0
4.12	6.18.40	2059c28bd725
4.12	7.1.5	d8ce67fa6a5e
4.12	7.2	6d7f7bcf225b