CVE-2026-98094

staging: fbtft: make dirty_lock IRQ-safe

Published Sep 25, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed

Description

In the Linux kernel, the following vulnerability has been resolved:

staging: fbtft: make dirty_lock IRQ-safe

fbtft_mkdirty() can be reached from the fbcon rendering path while
processing printk() in hardirq context. Meanwhile, dirty_lock is also
taken by fbtft_deferred_io() in workqueue context with local interrupts
enabled.

Lockdep reports a possible IRQ lock inversion involving dirty_lock and
console_owner. A hardirq can interrupt a CPU holding dirty_lock and
enter the console rendering path, which can attempt to acquire
dirty_lock again.

The following lockdep report was observed on an RK3566 system with
CONFIG_PROVE_LOCKING enabled:

WARNING: possible irq lock inversion dependency detected
swapper/2/0 just changed the state of lock:
(console_owner){-...}-{0:0}
but this lock took another, HARDIRQ-unsafe lock in the past:
(&par->dirty_lock){+.+.}-{2:2}

CPU0 CPU1
---- ----
lock(&par->dirty_lock);
local_irq_disable();
lock(console_owner);
lock(&par->dirty_lock);
<Interrupt>
lock(console_owner);

*** DEADLOCK ***

Use spin_lock_irqsave() for fbtft_mkdirty() and spin_lock_irq() for
fbtft_deferred_io(). They only access the dirty line range, so the
IRQ-off regions remain short.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< 0843298b159599ee7bc6d14800efdb4bc7349706
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< a323066337ed85c38decfc7f6bbf42f27605dff1
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< f2451e18826eb6a33ea51419f39bdd2eb99fa1ea
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< 10cc145b873670438d3b105133dffdae70822db6
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< 2a609e29efbba79f9abd68c4ec8a2bd7ecf291e7
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< f0c869df2c33793c8828acaab3e4a5e0176f9f00
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< dcb48fde8003492256dee45815144aa5ed26ce7c
`c296d5f9957c03994a699d6739c27d4581a9f6c7`	affected	< f576944a59f31bcffff121117ebf452c5dd162b7

Linux

affected

Version	Status	Constraints
`4.0`	affected	—
`0`	unaffected	< 4.0
`5.10.271`	unaffected	≤ 5.10.*
`5.15.222`	unaffected	≤ 5.15.*
`6.1.189`	unaffected	≤ 6.1.*
`6.6.158`	unaffected	≤ 6.6.*
`6.12.111`	unaffected	≤ 6.12.*
`6.18.53`	unaffected	≤ 6.18.*
`7.2.7`	unaffected	≤ 7.2.*
`7.3`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:7.3:rc1::::::

No data.

Vendor Product Versions

Linux

Linux Kernel

Version	Status	Scheme	Platform
`[c296d5f9957c03994a699d6739c27d4581a9f6c7,2a609e29efbba79f9abd68c4ec8a2bd7ecf291e7)`	affected	code_commit	—
`[c296d5f9957c03994a699d6739c27d4581a9f6c7,f0c869df2c33793c8828acaab3e4a5e0176f9f00)`	affected	code_commit	—
`[c296d5f9957c03994a699d6739c27d4581a9f6c7,dcb48fde8003492256dee45815144aa5ed26ce7c)`	affected	code_commit	—
`[c296d5f9957c03994a699d6739c27d4581a9f6c7,f576944a59f31bcffff121117ebf452c5dd162b7)`	affected	code_commit	—

Linux

Linux Kernel

Version	Status	Scheme	Platform
`4.0`	affected	generic	—
`[0,4.0)`	unaffected	semver	—
`[6.12.111,6.13.0)`	unaffected	semver	—
`[6.18.53,6.19.0)`	unaffected	semver	—
`[7.2.7,7.3.0)`	unaffected	semver	—
`[7.3-rc2,*]`	unaffected	generic	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Debian DLA	DLA-4817-1	linux-6.12 security update
Debian DLA	DLA-4841-1	linux security update
Debian DSA	DSA-6528-1	linux security update
Ubuntu USN	USN-8961-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9019-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9020-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9022-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9023-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9024-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9025-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9026-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9029-1	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-9039-1	Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN	USN-9040-1	Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN	USN-9066-1	Linux kernel (HWE) vulnerabilities
Ubuntu USN	USN-9091-1	Linux kernel (NVIDIA Tegra) vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.095% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/0843298b159599ee7bc6d14800efdb4bc7349706
https://git.kernel.org/stable/c/10cc145b873670438d3b105133dffdae70822db6
https://git.kernel.org/stable/c/2a609e29efbba79f9abd68c4ec8a2bd7ecf291e7
https://git.kernel.org/stable/c/a323066337ed85c38decfc7f6bbf42f27605dff1
https://git.kernel.org/stable/c/dcb48fde8003492256dee45815144aa5ed26ce7c
https://git.kernel.org/stable/c/f0c869df2c33793c8828acaab3e4a5e0176f9f00
https://git.kernel.org/stable/c/f2451e18826eb6a33ea51419f39bdd2eb99fa1ea
https://git.kernel.org/stable/c/f576944a59f31bcffff121117ebf452c5dd162b7

History

Oct 23, 2026 11:00 PM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses	CWE-1345 CWE-367

Oct 23, 2026 7:00 PM Weaknesses updated. Affected versions updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-667
CPEs		cpe:2.3:o:linux:linux_kernel:7.3:rc1::::::
Metrics		cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}`

Oct 3, 2026 11:15 AM Added references View changes

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/0843298b159599ee7bc6d14800efdb4bc7349706 https://git.kernel.org/stable/c/10cc145b873670438d3b105133dffdae70822db6 https://git.kernel.org/stable/c/a323066337ed85c38decfc7f6bbf42f27605dff1 https://git.kernel.org/stable/c/f2451e18826eb6a33ea51419f39bdd2eb99fa1ea

Sep 25, 2026 4:30 PM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-1345 CWE-367

Sep 25, 2026 10:30 AM Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references View changes

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: staging: fbtft: make dirty_lock IRQ-safe fbtft_mkdirty() can be reached from the fbcon rendering path while processing printk() in hardirq context. Meanwhile, dirty_lock is also taken by fbtft_deferred_io() in workqueue context with local interrupts enabled. Lockdep reports a possible IRQ lock inversion involving dirty_lock and console_owner. A hardirq can interrupt a CPU holding dirty_lock and enter the console rendering path, which can attempt to acquire dirty_lock again. The following lockdep report was observed on an RK3566 system with CONFIG_PROVE_LOCKING enabled: WARNING: possible irq lock inversion dependency detected swapper/2/0 just changed the state of lock: (console_owner){-...}-{0:0} but this lock took another, HARDIRQ-unsafe lock in the past: (&par->dirty_lock){+.+.}-{2:2} CPU0 CPU1 ---- ---- lock(&par->dirty_lock); local_irq_disable(); lock(console_owner); lock(&par->dirty_lock); <Interrupt> lock(console_owner); * DEADLOCK * Use spin_lock_irqsave() for fbtft_mkdirty() and spin_lock_irq() for fbtft_deferred_io(). They only access the dirty line range, so the IRQ-off regions remain short.
Title		staging: fbtft: make dirty_lock IRQ-safe
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/2a609e29efbba79f9abd68c4ec8a2bd7ecf291e7 https://git.kernel.org/stable/c/dcb48fde8003492256dee45815144aa5ed26ce7c https://git.kernel.org/stable/c/f0c869df2c33793c8828acaab3e4a5e0176f9f00 https://git.kernel.org/stable/c/f576944a59f31bcffff121117ebf452c5dd162b7