CVE-2026-43258
Memory Corruption in Linux Kernel During Compaction
Publication date: 2026-05-06
Last updated on: 2026-05-06
Assigner: kernel.org
Description
Description
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects Alpha systems running the Linux kernel when memory compaction is enabled. It causes sporadic user-space crashes and heap corruption due to insufficient Translation Lookaside Buffer (TLB) shootdown during page migration.
The root cause is that Alpha systems rely on ASN-based MM context rollover for instruction cache coherency, but this mechanism alone does not prevent stale data or instruction translations from persisting after page migration.
Symptoms include segmentation faults (SIGSEGV), failures in the glibc memory allocator (such as 'unaligned tcache chunk' errors), and compiler internal errors. These issues disappear if memory compaction is disabled or if global TLB invalidation is used.
The fix involves introducing a migration-specific helper that combines MM context invalidation, immediate per-CPU TLB invalidation, and synchronous cross-CPU shootdown to ensure proper memory and instruction cache coherency during page migration.
How can this vulnerability impact me? :
This vulnerability can cause sporadic crashes and heap corruption in user-space applications on Alpha systems running the Linux kernel with memory compaction enabled.
Such crashes may manifest as segmentation faults, memory allocator failures, or compiler errors, potentially leading to application instability, data loss, or unexpected behavior.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability manifests as sporadic user-space crashes and heap corruption on Alpha systems when memory compaction is enabled.
- Look for symptoms such as SIGSEGV (segmentation faults), glibc allocator failures like "unaligned tcache chunk", and compiler internal errors.
- Monitor system logs and application crash reports for these errors.
Since the issue is related to memory compaction and TLB shootdown on Alpha systems, detection involves observing these failure symptoms rather than specific network commands.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability immediately, disable memory compaction on affected Alpha systems.
Alternatively, use global TLB invalidation instead of relying on ASN-based MM context rollover.
Applying the kernel patch that introduces the migration-specific helper combining MM context invalidation, immediate per-CPU TLB invalidation, and synchronous cross-CPU shootdown will permanently fix the issue.