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CVE-2026-98094

staging: fbtft: make dirty_lock IRQ-safe PUBLISHED

Description (CNA)

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 (CNA)

Vendor / productVersions
Linux / Linuxaffected c296d5f9957c03994a699d6739c27d4581a9f6c7 before 0843298b159599ee7bc6d14800efdb4bc7349706; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before a323066337ed85c38decfc7f6bbf42f27605dff1; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before f2451e18826eb6a33ea51419f39bdd2eb99fa1ea; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before 10cc145b873670438d3b105133dffdae70822db6; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before 2a609e29efbba79f9abd68c4ec8a2bd7ecf291e7; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before f0c869df2c33793c8828acaab3e4a5e0176f9f00; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before dcb48fde8003492256dee45815144aa5ed26ce7c; affected c296d5f9957c03994a699d6739c27d4581a9f6c7 before f576944a59f31bcffff121117ebf452c5dd162b7
Linux / Linuxaffected 4.0; unaffected 0 before 4.0; unaffected 5.10.271 through 5.10.*; unaffected 5.15.222 through 5.15.*; unaffected 6.1.189 through 6.1.*; unaffected 6.6.158 through 6.6.*; unaffected 6.12.111 through 6.12.*; unaffected 6.18.53 through 6.18.*; unaffected 7.2.7 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References