CVE-2026-89598

A flaw was found in the Linux kernel's fbdev (framebuffer device) subsystem, specifically within the ssd1307fb driver. This vulnerability occurs when display damage callbacks, which handle updates to the display, perform synchronous I2C (Inter-Integrated Circuit) transfers from an atomic context. This can lead to a 'scheduling while atomic' bug, causing system instability or a denial of service (DoS) for a local user.

A LOW impact denial-of-service flaw was found in the Linux kernel's fbdev ssd1307fb driver as shipped in Red Hat Enterprise Linux 8 and 9 and in the RHCOS kernels of Red Hat OpenShift Container Platform 4. The ssd1307fb driver updates the display synchronously from its fbdev damage callbacks, which may run from fbcon while printk has disabled preemption. This enters the sleeping I2C transfer path from atomic context, triggering a 'scheduling while atomic' BUG and kernel warnings that can leave the system unstable or unavailable. A local user with low privileges can trigger this condition through normal console output on systems where an SSD1307-family display is attached over I2C. The kernels in Red Hat Enterprise Linux 6 and 7 (including kernel-rt) are not affected because the vulnerable code is not present. The Red Hat CVSS score for this flaw is 5.5 (MODERATE, CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Because the CVSS score is below 7.0, the fix is currently deferred per Red Hat's severity-based fix policy; the residual risk is limited to local denial of service, and only on the uncommon hardware configurations that use this driver.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.