{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-89756",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-11T19:38:34.763Z",
        "datePublished": "2026-09-11T19:46:59.093Z",
        "dateUpdated": "2026-10-19T08:52:09.900Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:52:09.900Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()\n\nmigrate_pages_batch() unmaps each folio before moving it, and every\nunmap runs the mmu_notifier invalidate callbacks.  On KVM hosts\ntry_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() ->\ntdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps\nthe CPU busy for a long time.\n\nThe loop already calls cond_resched(), but on PREEMPTION kernels that is\na no-op, and involuntary preemption is not a Tasks-RCU quiescent state.\n\nA long batch therefore never reports a quiescent state, and the\nmigrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the\nTasks-RCU grace period for minutes, which is common at Meta fleet:\n\n  INFO: rcu_tasks detected stalls on tasks:\n  0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0      state:R  running task\n  Call Trace:\n   tdp_mmu_zap_leafs\n   tdp_mmu_next_root\n   gfn_to_pfn_cache_invalidate_start\n   kvm_mmu_notifier_invalidate_range_start\n   __mmu_notifier_invalidate_range_start\n   try_to_migrate_one\n   try_to_migrate\n   migrate_pages_batch\n   migrate_pages\n   compact_zone\n   compact_node\n   kcompactd\n   kthread\n\nUse cond_resched_tasks_rcu_qs() so a quiescent state is reported even\nwhen cond_resched() does nothing.\n\nThis has also been discussed at [1]"
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/migrate.c"
                    ],
                    "versions": [
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "8c6d63d434ebb85c6cf3dac1e70a171b183c6614",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "4757542649af56d894e25e30f57cd497dffad53f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "4996a7bc01ef35570664854dac2530c604981039",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "5dc0daff0341c6baba19c38f47d299ac831d7e99",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "66734981b4d3c105223a13c827c9c73be18d91ad",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8315f42295d2667a7f942f154b73a86fd7cb2227",
                            "lessThan": "efe8f86c0916f0f74eea74ae21a3b37f728c6bad",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/migrate.c"
                    ],
                    "versions": [
                        {
                            "version": "3.18",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "3.18",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.188",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.157",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.109",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.50",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.4",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "6.1.188"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "6.6.157"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "6.12.109"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "6.18.50"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "7.2.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "3.18",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/8c6d63d434ebb85c6cf3dac1e70a171b183c6614"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4757542649af56d894e25e30f57cd497dffad53f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4996a7bc01ef35570664854dac2530c604981039"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5dc0daff0341c6baba19c38f47d299ac831d7e99"
                },
                {
                    "url": "https://git.kernel.org/stable/c/66734981b4d3c105223a13c827c9c73be18d91ad"
                },
                {
                    "url": "https://git.kernel.org/stable/c/efe8f86c0916f0f74eea74ae21a3b37f728c6bad"
                }
            ],
            "title": "mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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}