Null Pointer Dereference in Linux Kernel Affects Shared Memory Handling

CVE-2025-68293

What is CVE-2025-68293?

A vulnerability exists in the Linux kernel due to a flaw in handling shared memory when splitting huge pages. Specifically, an early check introduced in a code commit did not adequately validate the mapping pointer before accessing its flags. As a result, accessing mapping->flags with a NULL mapping pointer can lead to a null pointer dereference, potentially resulting in system instability or crashes. This vulnerability particularly affects shared memory folios in the swap cache and truncated folios, highlighting the importance of proper null checks in memory management routines.

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