Linux Kernel dm_ioctl Buffer Overflow Vulnerability

CVE-2026-99063

What is CVE-2026-99063?

In the Linux kernel, a buffer overflow vulnerability exists within the dm ioctl functionality. The issue arises from a miscalculation in the buffer size during input operations. Specifically, the struct dm_ioctl contains trailing padding, allowing a userspace request to potentially cause an out-of-bounds read when data_start is incorrectly set to the size of the struct without verifying the allocated buffer size. This oversight may lead to the disclosure of sensitive data adjacent to the memory allocation. Although this vulnerability requires root privileges to exploit, proper validation of the input buffer size is crucial for maintaining system integrity.

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