CVE-2025-38320: 
Linux Kernel vulnerability analysis and mitigation

A stack-out-of-bounds read vulnerability was discovered in the Linux kernel's arm64/ptrace functionality, specifically in the regsgetkernelstacknth() function. The vulnerability was assigned CVE-2025-38320 and was disclosed on July 10, 2025 (NVD, CVE).

The vulnerability manifests as a KASAN-reported stack-out-of-bounds read in the regsgetkernelstacknth() function. The issue appears to be related to the behavior of some gcc compilers and was previously fixed on the s390 architecture. The bug occurs when reading a value at *addr, even though regsgetkernelstacknth() has confirmed that addr is on the stack. The issue was detected through KASAN (Kernel Address Sanitizer) reporting a stack-out-of-bounds read at address ffff800089277c10 (NVD).

The vulnerability could potentially lead to information disclosure through unauthorized memory access, as it allows reading memory outside the intended stack boundaries. This could expose sensitive kernel information to attackers (NVD).

The fix involves using the READONCENOCHECK() helper to silence the KASAN check for this case, as the addr value has already been confirmed to be on the stack. This solution was implemented based on previous fixes for similar issues in the s390 architecture (NVD).