Answer in brief
CVE-2026-89756 records a Unknown severity vulnerability in mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4996a7bc01ef35570664854dac2530c604981039 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5dc0daff0341c6baba19c38f47d299ac831d7e99 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <66734981b4d3c105223a13c827c9c73be18d91ad || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <efe8f86c0916f0f74eea74ae21a3b37f728c6bad || >=0 <6.12.109 || >=0 <6.18.50 || >=0 <7.2.4 | 4996a7bc01ef35570664854dac2530c604981039, 5dc0daff0341c6baba19c38f47d299ac831d7e99, 66734981b4d3c105223a13c827c9c73be18d91ad, efe8f86c0916f0f74eea74ae21a3b37f728c6bad, 6.12.109, 6.18.50, 7.2.4 |
| Linux/Linuxgeneric | >=8315f42295d2667a7f942f154b73a86fd7cb2227 <4996a7bc01ef35570664854dac2530c604981039 || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <5dc0daff0341c6baba19c38f47d299ac831d7e99 || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <66734981b4d3c105223a13c827c9c73be18d91ad || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <efe8f86c0916f0f74eea74ae21a3b37f728c6bad | 4996a7bc01ef35570664854dac2530c604981039, 5dc0daff0341c6baba19c38f47d299ac831d7e99, 66734981b4d3c105223a13c827c9c73be18d91ad, efe8f86c0916f0f74eea74ae21a3b37f728c6bad |
| Linux/Linuxgeneric | 3.18 | Not reported |
| Linux/Linuxgeneric | >=8315f42295d2667a7f942f154b73a86fd7cb2227 <8c6d63d434ebb85c6cf3dac1e70a171b183c6614 || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <4757542649af56d894e25e30f57cd497dffad53f || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <4996a7bc01ef35570664854dac2530c604981039 || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <5dc0daff0341c6baba19c38f47d299ac831d7e99 || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <66734981b4d3c105223a13c827c9c73be18d91ad || >=8315f42295d2667a7f942f154b73a86fd7cb2227 <efe8f86c0916f0f74eea74ae21a3b37f728c6bad | 8c6d63d434ebb85c6cf3dac1e70a171b183c6614, 4757542649af56d894e25e30f57cd497dffad53f, 4996a7bc01ef35570664854dac2530c604981039, 5dc0daff0341c6baba19c38f47d299ac831d7e99, 66734981b4d3c105223a13c827c9c73be18d91ad, efe8f86c0916f0f74eea74ae21a3b37f728c6bad |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
In the Linux kernel, the following vulnerability has been resolved: mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch() migrate_pages_batch() unmaps each folio before moving it, and every unmap runs the mmu_notifier invalidate callbacks. On KVM hosts try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() -> tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps the CPU busy for a long time. The loop already calls cond_resched(), but on PREEMPTION kernels that is a no-op, and involuntary preemption is not a Tasks-RCU quiescent state. A long batch therefore never reports a quiescent state, and the migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the Tasks-RCU grace period for minutes, which is common at Meta fleet: INFO: rcu_tasks detected stalls on tasks: 0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task Call Trace: tdp_mmu_zap_leafs tdp_mmu_next_root gfn_to_pfn_cache_invalidate_start kvm_mmu_notifier_invalidate_range_start __mmu_notifier_invalidate_range_start try_to_migrate_one try_to_migrate migrate_pages_batch migrate_pages compact_zone compact_node kcompactd kthread Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even when cond_resched() does nothing. This has also been discussed at [1]
Quoted source text, attributed separately from HOL analysis.