Kernel NULL Pointer Dereference in Linux Kernel Affects HugeTLB Memory Management

CVE-2025-38050

What is CVE-2025-38050?

In the Linux kernel, a vulnerability exists that causes a kernel crash due to a NULL pointer dereference when replacing free hugetlb folios. This occurs during a potential race condition between memory handling functions within the kernel, where an attempt to access a hugetlb folio may yield a NULL pointer. The problem arises when one thread is in the process of updating and freeing a hugetlb folio while another concurrently replaces free hugetlb folios. Without proper locking mechanisms, the system can attempt to access an uninitialized memory location, leading to instability and crashes. The issue has been addressed by implementing more rigorous locking, ensuring that memory allocations do not result in dereferencing NULL pointers.

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