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CVE-2026-90228

nvmet: fix NULL pointer dereference in nvmet_execute_identify_ns_zns()

7.5 EPSS 0.7% AV:N

Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem drivers/nvme. Debian urgency: not yet assigned.

What to do, per Debian release

Debian's own status for CVE-2026-90228 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source

Release	Status	Version	What this means
Debian 12bookworm	fixedDLA-4841-1 · 2026-10-17 · text	6.1.190-1	Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts.
Debian 13trixie	fixedDSA-6528-1 · 2026-09-29 · text	6.12.111-1	Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts.
Debian 14forky	fixed	7.2.6-1	Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesid	fixed	7.2.6-1	Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian 12bookworm · linux-6.12	fixedDLA-4817-1 · 2026-10-04 · text	6.12.111-1~deb12u1	Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts.

The vulnerability

What the bug is

When a host issues an Identify command with CNS 05h (I/O Command Set specific Identify Namespace) and CSI 02h (ZNS) targeting a file-backed namespace, nvmet_execute_identify_ns_zns() calls bdev_is_zoned() on req->ns->bdev. A file-backed namespace has no block device, so req->ns->bdev is NULL and bdev_is_zoned() dereferences it, oopsing. The I/O command set is selected by the host-supplied CSI field and the command is routed here whenever CONFIG_BLK_DEV_ZONED is enabled, independent of the namespace backing type, so any file-backed namespace is exposed. Reject the command with Invalid Field when the namespace is not backed by a block device.

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/nvme/target/zns.c

What this is: NVM EXPRESS TARGET DRIVERMAINTAINERS section matched on drivers/nvme/target/ · linux-nvme@lists.infradead.org · Supported
Kernel module: nvmet

Check it on the machine

grep -wE 'CONFIG_BLK_DEV_ZONED|CONFIG_NVME_TARGET' /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 nvmet

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 as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.

bookworm, trixie, forky, sid, bookworm · linux-6.12m

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

Build switches: CONFIG_BLK_DEV_ZONED, CONFIG_NVME_TARGET
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

Debian tracker CVE record NVD kernel CNA record

Signals

Published: 2026-09-17 (31 days ago)source
CVSS: 7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsource recompute it
Attack vector: network (AV:N)source
EPSS: 0.67%, higher than 51.0% of all CVEssource
CISA KEV: not listedthe KEV catalogue
Debian urgency: not yet assignedsource
Subsystem: drivers/nvme

Upstream fixes

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

Introduced	Fixed in	Commit
5.14	5.15.221	1ce8faf90eb0
5.14	6.1.188	b873099944da
5.14	6.6.157	ff28a93a8959
5.14	6.12.110	cc29f7082b7a
5.14	6.18.52	1fb1236312ee
5.14	7.2.6	0b4cf43f9ca7
5.14	7.3	f594863967d8

Debian advisories

Advisory	Date	Shipped to	Debian
DLA-4841-1	2026-10-17	bookworm 6.1.190-1	tracker
DLA-4817-1	2026-10-04	bookworm 6.12.111-1~deb12u1	tracker
DSA-6528-1	2026-09-29	trixie 6.12.111-1	tracker

Why the CNA scored it this way

Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source

AV:NAttack vector, network: The host-controlled Identify capsule (opcode nvme_admin_identify) carries CNS 05h (NVME_ID_CNS_CS_NS) and CSI 02h (NVME_CSI_ZNS); nvmet-tcp receives that CapsuleCmd in nvmet_tcp_done_recv_pdu() after kernel_accept() and dispatches via nvmet_parse_admin_cmd()/nvmet_execute_identify() into nvmet_execute_identify_ns_zns().
AC:LAttack complexity, low: The attacker sets identify.cns and identify.csi on Identify for any enabled file-backed NSID; nvmet_execute_identify() routes CSI=ZNS to nvmet_execute_identify_ns_zns() whenever CONFIG_BLK_DEV_ZONED is built in, then bdev_is_zoned(req->ns->bdev) hits NULL with no race or layout dependency.
PR:NPrivileges required, none: nvmet_check_ctrl_status() after Connect/CC.EN only enforces DH-HMAC-CHAP when a host_key exists; nvmet_check_auth_status() otherwise returns true, nvmet_host_allowed() treats host NQN as an asserted identifier, and allow_any_host subsystems accept any initiator with no Linux credentials.
UI:NUser interaction, none: The remote initiator itself sends Connect, Property Set of CC.EN, then the crafted Identify; no local user must mount a device, open a file, or otherwise interact.
S:UScope, unchanged: The oops occurs in the target kernel's nvmet-tcp worker while executing nvmet_execute_identify_ns_zns() and stays in that host's kernel authority; it is not a VM escape or IOMMU/sandbox boundary bypass.
C:NConfidentiality impact, none: bdev_is_zoned() only loads bdev->bd_queue through the NULL ns->bdev of a file-backed namespace; nvmet_execute_identify_ns_zns() crashes before nvmet_copy_to_sgl() of the identify buffer, so no kernel data is returned.
I:NIntegrity impact, none: The fault is a NULL read in bdev_get_queue() via bdev_is_zoned(); no kernel object is overwritten and a pure NULL dereference does not yield a write or control-flow primitive.
A:HAvailability impact, high: Calling bdev_is_zoned(req->ns->bdev) with a NULL file-backed bdev in nvmet_execute_identify_ns_zns() oopses the kernel, crashing the NVMe target.