Memory Leak in Linux Kernel Affecting Shared Memory Mapping

CVE-2026-31654

What is CVE-2026-31654?

A memory leak vulnerability was identified in the Linux kernel related to the handling of shared memory mapping. When the /dev/zero device is mapped with MAP_SHARED, a failure in the process can lead to a situation where a newly created shared memory file is not properly released. The error occurs in the __mmap_region() function when an error path is not adequately managed. Specifically, while the original file allocated is released correctly, the new shared memory file created during the process remains untracked and not freed, leading to potential memory exhaustion. This can be demonstrated through fault injection tests, revealing unreferenced objects and indicating that the system continues to allocate memory without proper deallocation. Immediate attention is recommended for users operating systems using the affected Linux kernel versions.

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