CVE-2025-39714: 
Linux Debian vulnerability analysis and mitigation

CVE-2025-39714 is a vulnerability discovered in the Linux kernel affecting the media subsystem, specifically the USB TV driver (usbtv). The issue was disclosed on September 5, 2025, and involves a resolution locking problem while streaming (NVD).

The vulnerability occurs when a program is streaming (using ffplay) and another program (qv4l2) changes the TV standard from NTSC to PAL, causing the kernel to crash due to attempting to copy to unmapped memory. The root cause is that changing from NTSC to PAL increases the resolution in the usbtv struct, but the video plane buffer isn't adjusted, resulting in a buffer overflow. The fix involves calling vb2isbusy instead of vb2isstreaming (NVD). The vulnerability has been assigned a CVSS v3 base score of 5.5 (Rapid7).

When exploited, this vulnerability can cause a kernel crash, leading to system instability and potential denial of service. The issue specifically affects systems using the USB TV driver functionality in the Linux kernel (NVD).

The vulnerability has been resolved in the Linux kernel through a patch that modifies the resolution locking mechanism. The fix implements proper buffer adjustment when changing TV standards and uses vb2isbusy instead of vb2isstreaming (NVD).