Executive brief
A vulnerability in the Linux kernel's memory management for Alpha-based systems can lead to unpredictable application crashes and data corruption. This occurs when the system attempts to reorganize memory to improve performance, but fails to properly clear old records of where data is stored. An attacker or a malfunctioning program could exploit this to corrupt sensitive information or cause a complete system failure.
Technical details
A vulnerability in the Linux kernel's Alpha architecture implementation stems from insufficient Translation Lookaside Buffer (TLB) shootdowns during page migration and memory compaction. While Alpha relies on Address Space Number (ASN) based context rollovers for instruction cache coherency, this mechanism is insufficient to prevent stale data or instruction translations from persisting after migration. An attacker with local access can trigger memory compaction to cause out-of-bounds writes (CWE-787) or heap corruption, leading to SIGSEGV or allocator failures. The fix introduces a migration-specific helper that synchronizes MM context invalidation, per-CPU TLB invalidation, and cross-CPU shootdowns. Patches have been released for multiple stable kernel branches including 6.12.75, 6.18.16, and 6.19.6.
Affected products
- Linux Linux Kernel 6.13 to 6.18.16, 6.19 to 6.19.6, 2.6.16.1 to 6.12.75
Timeline
- 2026-05-06: advisory: Initial disclosure by kernel.org
- 2026-05-06: disclosed
- 2026-03-04: patched: Fix committed to stable trees