CVE-2025-38214: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-38214 is a vulnerability discovered in the Linux kernel's framebuffer device (fbdev) subsystem, specifically affecting the fbsetvar functionality. The vulnerability was disclosed on July 4, 2025, and was identified by the Linux Verification Center using the Syzkaller fuzzing tool (NVD).

The vulnerability occurs when fbaddvideomode() in fbsetvar() fails to allocate memory for fbvideomode, which can lead to a null-pointer dereference in fbvideomodetovar(). This happens because the fbinfo is registered while missing the expected mode in modelist that is described in fbinfo->var. The issue manifests as a general protection fault for non-canonical address 0xdffffc0000000001 (Debian Tracker).

The vulnerability can result in a null pointer dereference in the Linux kernel's framebuffer subsystem, potentially leading to system crashes or denial of service conditions. This affects systems using the framebuffer device interface for display output (NVD).

The vulnerability has been fixed in the Linux kernel by implementing proper error handling in fbsetvar() to restore the old value of fb_info->var on failure, similar to existing error handling patterns in the function. Fixed versions are available in Linux kernel 6.12.35-1 and later (Debian Tracker).