Linux Kernel Infinite Recursion Vulnerability in Memory Buffer Allocation

CVE-2025-38690

What is CVE-2025-38690?

A vulnerability exists in the Linux kernel due to improper handling of buffer allocation for the DRM (Direct Rendering Manager) subsystem. When the buffer plus offset is not aligned to the XE_CACHELINE_BYTES, a fallback mechanism allocates the buffer on the stack. If this buffer also misaligns, it causes the function to recurse indefinitely. This leads to a potential stack overflow, resulting in a kernel panic as the system resources are exhausted. The vulnerability has been addressed by transitioning from stack allocation to kmalloc, ensuring correct memory alignment and preventing the recursion issue.

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