{"api_version":"1","generated_at":"2026-05-06T17:16:08+00:00","cve":"CVE-2026-43258","urls":{"html":"https://cve.report/CVE-2026-43258","api":"https://cve.report/api/cve/CVE-2026-43258.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43258","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43258"},"summary":{"title":"alpha: fix user-space corruption during memory compaction","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nalpha: fix user-space corruption during memory compaction\n\nAlpha systems can suffer sporadic user-space crashes and heap\ncorruption when memory compaction is enabled.\n\nSymptoms include SIGSEGV, glibc allocator failures (e.g. \"unaligned\ntcache chunk\"), and compiler internal errors. The failures disappear\nwhen compaction is disabled or when using global TLB invalidation.\n\nThe root cause is insufficient TLB shootdown during page migration.\nAlpha relies on ASN-based MM context rollover for instruction cache\ncoherency, but this alone is not sufficient to prevent stale data or\ninstruction translations from surviving migration.\n\nFix this by introducing a migration-specific helper that combines:\n  - MM context invalidation (ASN rollover),\n  - immediate per-CPU TLB invalidation (TBI),\n  - synchronous cross-CPU shootdown when required.\n\nThe helper is used only by migration/compaction paths to avoid changing\nglobal TLB semantics.\n\nAdditionally, update flush_tlb_other(), pte_clear(), to use\nREAD_ONCE()/WRITE_ONCE() for correct SMP memory ordering.\n\nThis fixes observed crashes on both UP and SMP Alpha systems.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-06 12:16:46","updated_at":"2026-05-06 13:07:51"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f","name":"https://git.kernel.org/stable/c/03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dd5712f3379cfe760267cdd28ff957d9ab4e51c7","name":"https://git.kernel.org/stable/c/dd5712f3379cfe760267cdd28ff957d9ab4e51c7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6","name":"https://git.kernel.org/stable/c/d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bab8d762a8dbb816b10011e13b87d1bca91e5f77","name":"https://git.kernel.org/stable/c/bab8d762a8dbb816b10011e13b87d1bca91e5f77","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43258","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43258","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 bab8d762a8dbb816b10011e13b87d1bca91e5f77 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 dd5712f3379cfe760267cdd28ff957d9ab4e51c7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.75 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.16 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.6 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/alpha/include/asm/pgtable.h","arch/alpha/include/asm/tlbflush.h","arch/alpha/mm/Makefile","arch/alpha/mm/tlbflush.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"bab8d762a8dbb816b10011e13b87d1bca91e5f77","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"dd5712f3379cfe760267cdd28ff957d9ab4e51c7","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/alpha/include/asm/pgtable.h","arch/alpha/include/asm/tlbflush.h","arch/alpha/mm/Makefile","arch/alpha/mm/tlbflush.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.75","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.16","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.75","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nalpha: fix user-space corruption during memory compaction\n\nAlpha systems can suffer sporadic user-space crashes and heap\ncorruption when memory compaction is enabled.\n\nSymptoms include SIGSEGV, glibc allocator failures (e.g. \"unaligned\ntcache chunk\"), and compiler internal errors. The failures disappear\nwhen compaction is disabled or when using global TLB invalidation.\n\nThe root cause is insufficient TLB shootdown during page migration.\nAlpha relies on ASN-based MM context rollover for instruction cache\ncoherency, but this alone is not sufficient to prevent stale data or\ninstruction translations from surviving migration.\n\nFix this by introducing a migration-specific helper that combines:\n  - MM context invalidation (ASN rollover),\n  - immediate per-CPU TLB invalidation (TBI),\n  - synchronous cross-CPU shootdown when required.\n\nThe helper is used only by migration/compaction paths to avoid changing\nglobal TLB semantics.\n\nAdditionally, update flush_tlb_other(), pte_clear(), to use\nREAD_ONCE()/WRITE_ONCE() for correct SMP memory ordering.\n\nThis fixes observed crashes on both UP and SMP Alpha systems."}],"providerMetadata":{"dateUpdated":"2026-05-06T11:28:46.536Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/d4ca6ca2c6f5a1d19d9014c5b36d96637846b5d6"},{"url":"https://git.kernel.org/stable/c/03e42b5f7ad4c2c3db8bd384bab7990d5d53c90f"},{"url":"https://git.kernel.org/stable/c/bab8d762a8dbb816b10011e13b87d1bca91e5f77"},{"url":"https://git.kernel.org/stable/c/dd5712f3379cfe760267cdd28ff957d9ab4e51c7"}],"title":"alpha: fix user-space corruption during memory compaction","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43258","datePublished":"2026-05-06T11:28:46.536Z","dateReserved":"2026-05-01T14:12:55.997Z","dateUpdated":"2026-05-06T11:28:46.536Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-06 12:16:46","lastModifiedDate":"2026-05-06 13:07:51","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43258","Ordinal":"1","Title":"alpha: fix user-space corruption during memory compaction","CVE":"CVE-2026-43258","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43258","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nalpha: fix user-space corruption during memory compaction\n\nAlpha systems can suffer sporadic user-space crashes and heap\ncorruption when memory compaction is enabled.\n\nSymptoms include SIGSEGV, glibc allocator failures (e.g. \"unaligned\ntcache chunk\"), and compiler internal errors. The failures disappear\nwhen compaction is disabled or when using global TLB invalidation.\n\nThe root cause is insufficient TLB shootdown during page migration.\nAlpha relies on ASN-based MM context rollover for instruction cache\ncoherency, but this alone is not sufficient to prevent stale data or\ninstruction translations from surviving migration.\n\nFix this by introducing a migration-specific helper that combines:\n  - MM context invalidation (ASN rollover),\n  - immediate per-CPU TLB invalidation (TBI),\n  - synchronous cross-CPU shootdown when required.\n\nThe helper is used only by migration/compaction paths to avoid changing\nglobal TLB semantics.\n\nAdditionally, update flush_tlb_other(), pte_clear(), to use\nREAD_ONCE()/WRITE_ONCE() for correct SMP memory ordering.\n\nThis fixes observed crashes on both UP and SMP Alpha systems.","Type":"Description","Title":"alpha: fix user-space corruption during memory compaction"}]}}}