CVE-2026-98094staging: fbtft: make dirty_lock IRQ-safe

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.

CVSS

Not yet scored

Weakness (CWE)

Not given

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Linux

NVD analysis

Undergoing Analysis

Record last updated

Oct 3, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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