SB2026092894 - Deadlock in Linux kernel staging fbtft driver

Description

This security bulletin contains information about 1 vulnerability.

1) Deadlock (CVE-ID: CVE-2026-98094)

CWE-ID: CWE-833 - Deadlock

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an IRQ-unsafe locking mechanism in the fbtft dirty_lock handling in fbtft_mkdirty() and fbtft_deferred_io() when framebuffer console rendering occurs in hardirq context concurrently with deferred I/O workqueue processing. A local user can trigger concurrent framebuffer console rendering and deferred I/O processing to cause a denial of service.

Remediation

Install update from vendor's website.

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