Linux Kernel HugeTLBFS Memory Corruption Vulnerability

A vulnerability in the Linux kernel's HugeTLBFS implementation could lead to memory corruption. When a poisoned HugeTLB page is detected, it is currently removed from the page cache. This removal causes future attempts to map or read the huge page to allocate a new one, instead of notifying the user of the poisoning. The vulnerability has been addressed by modifying this behavior. The page is now retained in the page cache, and if a poisoned HugeTLB page is accessed via a syscall, the syscall will fail with an I/O error. Similarly, mapping the page will result in a specific SIGBUS error.

Impact

Exploitation of this vulnerability could cause memory corruption by allowing poisoned HugeTLB pages to be incorrectly handled, potentially leading to erroneous memory operations or data corruption.