CVE-2022-50781 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
amdgpu/pm: prevent array underflow in vega20_odn_edit_dpm_table()
In the PP_OD_EDIT_VDDC_CURVE case the "input_index" variable is capped at 2 but not checked for negative values so it results in an out of bounds read. This value comes from the user via sysfs.
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability CVE-2022-50781 affects the Linux kernel's amdgpu driver, specifically within the power management subsystem responsible for handling graphics processing unit operations. This issue resides in the vega20_odn_edit_dpm_table function which manages dynamic power management tables for AMD Radeon graphics cards. The flaw manifests when processing PP_OD_EDIT_VDDC_CURVE operations through the sysfs interface, creating a critical security risk that could potentially allow privilege escalation or system instability. The vulnerability is categorized under CWE-129 as an insufficient input validation, specifically addressing improper handling of array indices that could lead to memory access violations.
The technical implementation of this vulnerability stems from inadequate bounds checking in the input_index variable handling within the power management code path. While the code properly caps the input_index value at 2 to prevent exceeding array bounds in the positive direction, it fails to validate for negative values which would result in array underflow conditions. When malicious or malformed input is provided through the sysfs interface, the negative index value causes the code to access memory locations before the beginning of the allocated array, leading to out of bounds read operations. This type of memory corruption can result in unpredictable behavior including system crashes, data corruption, or potentially arbitrary code execution depending on the memory layout and exploitation circumstances. The vulnerability directly relates to ATT&CK technique T1068 which involves privilege escalation through local system exploits.
The operational impact of CVE-2022-50781 extends beyond simple system instability to potentially compromise the entire system security posture when exploited. Systems running affected Linux kernel versions with AMD graphics hardware become vulnerable to local privilege escalation attacks, as attackers can leverage this flaw to gain elevated privileges through carefully crafted sysfs inputs. The vulnerability affects all AMD Radeon graphics cards utilizing the vega20 power management tables, including those in servers, workstations, and desktop systems. Given that the input originates from user-space through sysfs interfaces, exploitation requires local access to the system but could be particularly dangerous in multi-user environments where unprivileged users might attempt to escalate their privileges. The memory corruption resulting from array underflow can trigger kernel panic conditions or create exploitable memory states that advanced attackers could leverage for more sophisticated attacks.
Mitigation strategies for CVE-2022-50781 primarily involve applying the official kernel patches released by the Linux kernel security team, which implement proper bounds checking for the input_index variable to prevent negative values from causing array underflow conditions. System administrators should prioritize updating their kernel versions to include the fix, particularly in production environments where AMD graphics hardware is deployed. Additional protective measures include restricting access to the affected sysfs interfaces through proper file permissions and access controls, implementing monitoring for unusual sysfs access patterns, and considering the deployment of kernel hardening measures such as stack canaries and address space layout randomization. Organizations should also conduct vulnerability assessments to identify systems running affected kernel versions and implement comprehensive patch management procedures to ensure all graphics-related components remain up to date with security fixes. The fix specifically addresses the root cause by ensuring input validation occurs before array access operations, preventing the negative index values from creating memory access violations that could be exploited for privilege escalation or system compromise.