CVE-2022-50781: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50781 is a Linux kernel vulnerability in the AMD GPU power management subsystem (amdgpu/pm) that allows a local user to trigger an out-of-bounds read via the sysfs interface. Specifically, the vega20_odn_edit_dpm_table() function in the PP_OD_EDIT_VDDC_CURVE case fails to validate the input_index variable for negative values, even though it is capped at 2, resulting in an array underflow. The vulnerability was published on December 24, 2025, and affects Linux kernel versions from commit d5bf26539494 onward across multiple stable branches. The CVSS base score is listed as 0.0 (no official CVSS rating assigned), with Feedly estimating severity as Medium (Feedly, EUVD).

The root cause is improper input validation (CWE-125: Out-of-bounds Read) in the vega20_odn_edit_dpm_table() function within the Linux kernel's amdgpu driver. When a user writes to the relevant sysfs attribute to edit the VDDC curve (PP_OD_EDIT_VDDC_CURVE), the input_index value is bounded above at 2 but is never checked for negative values. A negative index causes an array underflow — reading memory before the start of the target array — which is a classic out-of-bounds read condition. The vulnerability is reachable by a local user with access to the sysfs interface, typically requiring write access to the relevant sysfs node on a system with a supported AMD Vega20 GPU (Feedly, EUVD).

Successful exploitation results in an out-of-bounds read of kernel memory, which could lead to information disclosure of sensitive kernel data or, in some scenarios, contribute to a kernel crash (denial of service). The vulnerability is locally exploitable and requires access to the sysfs interface on a system with an AMD Vega20 GPU. There is no evidence of remote exploitability or direct code execution impact, limiting the scope primarily to confidentiality and availability on affected systems (Feedly, EUVD).

The Linux kernel maintainers have released patches across multiple stable branches. Fixed versions include kernel 5.4.229, 5.10.163, 5.15.86, 6.0.16, 6.1.2, and 6.2. Users should update to a patched kernel version for their distribution. The fix adds a check to ensure input_index is not negative before using it as an array index in vega20_odn_edit_dpm_table(). As a temporary workaround, restricting unprivileged user access to the relevant sysfs attributes (e.g., via udev rules or file permissions) can reduce exposure (EUVD, Linux Kernel Patch 5.15).