CVE-2026-80831

What the bug is

mxs_dcp_aes_block_crypt() uses sg_dma_len() without mapping the source scatterlist with dma_map_sg() first. Therefore, sg_dma_len() is invalid and could return zero or a stale DMA length, causing encryption and decryption to process the wrong number of bytes when CONFIG_NEED_SG_DMA_LENGTH=y. Use the original scatterlist length instead.

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/crypto/mxs-dcp.c

What this is

CRYPTO APIMAINTAINERS section matched on drivers/crypto/ · linux-crypto@vger.kernel.org · Maintained

Kernel module

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

Check it on the machine

grep -wE 'CONFIG_CRYPTO|CONFIG_CRYPTO_DEV_MXS_DCP' /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 5 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, sid, bookworm · linux-6.12n

n

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

Build switches

CONFIG_CRYPTO, CONFIG_CRYPTO_DEV_MXS_DCP

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

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 5.3% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/crypto

Upstream fixes

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

Introduced	Fixed in	Commit
3.14	5.10.269	fd0f211b27a6
3.14	5.15.220	04201dcc88b2
3.14	6.1.187	e72a795df521
3.14	6.6.156	1537bd55b4f8
3.14	6.12.108	da14fae5203b
3.14	6.18.49	182f16a20d32
3.14	7.1.13	0e9edb108a63
3.14	7.2.3	6ef9a4afb52c
3.14	7.3	c5bcb084a987

Debian advisories