CVE-2024-53098: 
Linux Debian vulnerability analysis and mitigation

CVE-2024-53098 affects the Linux kernel's DRM (Direct Rendering Manager) subsystem, specifically in the XE graphics driver's user fence handling. The vulnerability was discovered and disclosed on November 25, 2024. The issue exists because the access_ok() function only checks for address overflow but doesn't validate if the address sent from userspace is actually valid for access (NVD).

The vulnerability is present in the xesync.c file within the XE graphics driver. The issue stems from insufficient validation of user-provided addresses in the userfencecreate function. The original code only used accessok() to check for address overflow, which was inadequate for ensuring the validity of userspace addresses. The CVSS v3.1 base score is 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, indicating local access requirements but high impact potential (NVD).

The vulnerability could allow a local attacker to potentially cause system instability or execute arbitrary code through the manipulation of invalid memory addresses. This affects Linux kernel versions up to (excluding) 6.11.9, as well as various release candidates of version 6.12 (NVD).

The vulnerability has been fixed by adding additional validation through a prefetch operation to catch invalid addresses. The fix involves modifying the userfencecreate function to use get_user() to attempt reading the address before proceeding with fence creation. The patch has been implemented in kernel version 6.11.9 and later versions (Kernel Patch).