{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-71078", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:30:19.648Z", "datePublished": "2026-01-13T15:34:43.437Z", "dateUpdated": "2026-08-05T12:11:54.417Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:11:54.417Z" }, "descriptions": [ { "lang": "en", "value": "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---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - An attacker reaches the vulnerable SLB preload path through local execve() execution and induced scheduler migrations; it is not directly reachable through network traffic.\nAC:L - The attacker can repeatedly execute processes, induce context switches, and control migrations using same-owner CPU-affinity operations until the 8-bit load_slb counter wraps, without depending on victim-controlled state.\nPR:L - Ordinary unprivileged users may execute binaries and modify the affinity of their own processes; no capability, namespace privilege, or administrative access is required.\nUI:N - Exploitation is performed entirely through attacker-controlled processes and scheduling activity without requiring another user to take an action.\nS:U - The vulnerable process and affected kernel or partition remain within the same host security authority; this is not inherently a guest-to-host or other cross-scope escape.\nC:H - SLB corruption affects hardware address translation, and Power hardware can combine the VSIDs of multiple matching entries before raising the machine check. In the highest defensible case, an unintended translation can expose arbitrary mapped memory.\nI:H - The same unintended hardware translation can redirect stores and corrupt arbitrary memory or control data, potentially enabling privilege escalation or code execution.\nA:H - An SLB multihit generates a synchronous machine-check exception and warning; unsuccessful recovery, panic-on-warning configurations, or repeated triggering can crash the kernel or terminate the partition." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/book3s/64/mmu-hash.h", "arch/powerpc/kernel/process.c", "arch/powerpc/mm/book3s64/internal.h", "arch/powerpc/mm/book3s64/mmu_context.c", "arch/powerpc/mm/book3s64/slb.c" ], "versions": [ { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "01324c0328181b94cf390bda22ff91c75126ea57", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "2e9a95d60f1df7b57618fd5ef057aef331575bd2", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "c9f865022a1823d814032a09906e91e4701a35fc", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "b13a3dbfa196af68eae2031f209743735ad416bf", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "895123c309a34d2cfccf7812b41e17261a3a6f37", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "4ae1e46d8a290319f33f71a2710a1382ba5431e8", "status": "affected", "versionType": "git" }, { "version": "5434ae74629af58ad0fc27143a9ea435f7734410", "lessThan": "00312419f0863964625d6dcda8183f96849412c6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/book3s/64/mmu-hash.h", "arch/powerpc/kernel/process.c", "arch/powerpc/mm/book3s64/internal.h", "arch/powerpc/mm/book3s64/mmu_context.c", "arch/powerpc/mm/book3s64/slb.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.248", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.198", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.160", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.120", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.64", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.4", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "4.20", "versionEndExcluding": "5.10.248" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.198" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/01324c0328181b94cf390bda22ff91c75126ea57" }, { "url": "https://git.kernel.org/stable/c/2e9a95d60f1df7b57618fd5ef057aef331575bd2" }, { "url": "https://git.kernel.org/stable/c/c9f865022a1823d814032a09906e91e4701a35fc" }, { "url": "https://git.kernel.org/stable/c/b13a3dbfa196af68eae2031f209743735ad416bf" }, { "url": "https://git.kernel.org/stable/c/895123c309a34d2cfccf7812b41e17261a3a6f37" }, { "url": "https://git.kernel.org/stable/c/4ae1e46d8a290319f33f71a2710a1382ba5431e8" }, { "url": "https://git.kernel.org/stable/c/00312419f0863964625d6dcda8183f96849412c6" } ], "title": "powerpc/64s/slb: Fix SLB multihit issue during SLB preload", "x_generator": { "engine": "bippy-1.2.0" } } } }