CVE-2026-97989

What the bug is

vduse_validate_config() only checks the upper bound of vq_align. Invalid values can therefore reach vring_create_virtqueue_map(). The split-ring helpers use align - 1 as a bit mask, so the alignment must be a non-zero power of two. A zero value makes vring_size() drop the descriptor and available-ring part and vring_init() leave the used ring pointer NULL. The VIRTIO spec requires the used ring to start at an address aligned to at least 4 bytes. Reject values below VRING_USED_ALIGN_SIZE as well as non-power-of-two values before they reach the virtio ring helpers. Opening a virtio-net device created with vq_align=0 triggered: BUG: KASAN: null-ptr-deref in virtqueue_kick_prepare_split+0xe3/0x100 Read of size 2 at addr 0000000000000000 by task systemd-network/1062 Call Trace (relevant frames): dump_stack_lvl print_report kasan_report __asan_load2 virtqueue_kick_prepare_split+0xe3/0x100 virtqueue_kick_prepare+0x40/0x60 try_fill_recv+0x857/0x1250 virtnet_open+0x189/0x460 __dev_open+0x225/0x390 __dev_change_flags+0x368/0x3b0 netif_change_flags+0x56/0xc0 do_setlink.isra.0+0x68c/0x1e30 Validate the value before it reaches the virtio ring helpers.

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/vdpa/vdpa_user/vduse_dev.c

What this is

VIRTIO COREMAINTAINERS section matched on drivers/vdpa/ · virtualization@lists.linux.dev · Maintained

Kernel module

vduse

Check it on the machine

grep -wE 'CONFIG_VDPA|CONFIG_VDPA_USER' /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 vduse

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 riscv64/riscv64
• forky, sidm

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

m

a loadable module on every flavour - check lsmod, can be blacklisted

Build switches

CONFIG_VDPA, CONFIG_VDPA_USER

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

2026-09-25 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 5.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/vdpa

Upstream fixes

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

Introduced	Fixed in	Commit
5.15	6.18.57	831dab9b9bcc
5.15	7.2.7	c3c3b0839a11
5.15	7.3	fa2c25b4add5