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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 25 Sep 2026 10:30:00 +0000
| 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 |
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-25T10:24:25.889Z
Reserved: 2026-09-25T10:19:56.076Z
Link: CVE-2026-98094
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-25T11:17:39.133
Modified: 2026-09-25T11:17:39.133
Link: CVE-2026-98094
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.