{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2025-71078", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-71078", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2026-01-13T15:34:43.437Z", "updatedAt": "2026-10-19T18:15:11.106Z", "importedAt": "2026-10-24T01:57:44.935Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "powerpc/64s/slb: Fix SLB multihit issue during SLB preload", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s/slb: Fix SLB multihit issue during SLB preload\n\nOn systems using the hash MMU, there is a software SLB preload cache that\nmirrors the entries loaded into the hardware SLB buffer. This preload\ncache is subject to periodic eviction — typically after every 256 context\nswitches — to remove old entry.\n\nTo optimize performance, the kernel skips switch_mmu_context() in\nswitch_mm_irqs_off() when the prev and next mm_struct are the same.\nHowever, on hash MMU systems, this can lead to inconsistencies between\nthe hardware SLB and the software preload cache.\n\nIf an SLB entry for a process is evicted from the software cache on one\nCPU, and the same process later runs on another CPU without executing\nswitch_mmu_context(), the hardware SLB may retain stale entries. If the\nkernel then attempts to reload that entry, it can trigger an SLB\nmulti-hit error.\n\nThe following timeline shows how stale SLB entries are created and can\ncause a multi-hit error when a process moves between CPUs without a\nMMU context switch.\n\nCPU 0 CPU 1\n----- -----\nProcess P\nexec swapper/1\n load_elf_binary\n begin_new_exc\n activate_mm\n switch_mm_irqs_off\n switch_mmu_context\n switch_slb\n /*\n * This invalidates all\n * the entries in the HW\n * and setup the new HW\n * SLB entries as per the\n * preload cache.\n */\ncontext_switch\nsched_migrate_task migrates process P to cpu-1\n\nProcess swapper/0 context switch (to process P)\n(uses mm_struct of Process P) switch_mm_irqs_off()\n switch_slb\n load_slb++\n /*\n * load_slb becomes 0 here\n * and we evict an entry from\n * the preload cache with\n * preload_age(). We still\n * keep HW SLB and preload\n * cache in sync, that is\n * because all HW SLB entries\n * anyways gets evicted in\n * switch_slb during SLBIA.\n * We then only add those\n * entries back in HW SLB,\n * which are currently\n * present in preload_cache\n * (after eviction).\n */\n load_elf_binary continues...\n setup_new_exec()\n slb_setup_new_exec()\n\n sched_switch event\n sched_migrate_task migrates\n process P to cpu-0\n\ncontext_switch from swapper/0 to Process P\n switch_mm_irqs_off()\n /*\n * Since both prev and next mm struct are same we don't call\n * switch_mmu_context(). This will cause the HW SLB and SW preload\n * cache to go out of sync in preload_new_slb_context. Because there\n * was an SLB entry which was evicted from both HW and preload cache\n * on cpu-1. Now later in preload_new_slb_context(), when we will try\n * to add the same preload entry again, we will add this to the SW\n * preload cache and then will add it to the HW SLB. Since on cpu-0\n * this entry was never invalidated, hence adding this entry to the HW\n * SLB will cause a SLB multi-hit error.\n */\nload_elf_binary cont\n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "01324c0328181b94cf390bda22ff91c75126ea57" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "2e9a95d60f1df7b57618fd5ef057aef331575bd2" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "c9f865022a1823d814032a09906e91e4701a35fc" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "b13a3dbfa196af68eae2031f209743735ad416bf" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "895123c309a34d2cfccf7812b41e17261a3a6f37" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "4ae1e46d8a290319f33f71a2710a1382ba5431e8" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "status": "affected", "versionType": "git", "lessThan": "00312419f0863964625d6dcda8183f96849412c6" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.20" }, { "version": "5.10.248", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.198", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.160", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.120", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.64", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.4", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "6.19", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }