CVE-2026-90221

What the bug is

nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse the CORE_INIT_RSP packet without validating that the skb contains enough data. A malformed response (e.g. injected via virtual_ncidev) can declare a large num_supported_rf_interfaces while providing insufficient data, causing reads of uninitialized slab memory. This is later used in nci_init_complete_req(), triggering a KMSAN uninit-value warning. Add skb length checks before accessing packet fields: - Validate the skb has at least 1 byte for the status field. - Validate the skb can hold the fixed-size header before parsing. - In v2, bounds-check each variable-length rf_interface entry and its extension parameters within the parsing loop. - In v1, verify the skb is large enough for both the variable-length rf_interfaces array and the trailing rsp_2 structure.

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.

net/nfc/nci/rsp.c

What this is

NFC SUBSYSTEMMAINTAINERS section matched on net/nfc/ · oe-linux-nfc@lists.linux.dev · Maintained

Kernel module

nci

Check it on the machine

grep -wE 'CONFIG_NFC|CONFIG_NFC_NCI' /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 nci

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.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

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

Build switches

CONFIG_NFC, CONFIG_NFC_NCI

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

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 11.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

net/nfc

Upstream fixes

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

Introduced	Fixed in	Commit
5.11	5.15.221	baed3fdf6ed2
5.11	6.1.188	2f434478771a
5.11	6.6.157	5487f04c1ccb
5.11	6.12.110	bbe68e8249e2
5.11	6.18.52	4f0483bbcdac
5.11	7.2.6	7d44b897bff8
5.11	7.3	d56575a2595e

Debian advisories