{"api_version":"1","generated_at":"2026-05-06T20:29:30+00:00","cve":"CVE-2026-31577","urls":{"html":"https://cve.report/CVE-2026-31577","api":"https://cve.report/api/cve/CVE-2026-31577.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31577","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31577"},"summary":{"title":"nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map\n\nThe DAT inode's btree node cache (i_assoc_inode) is initialized lazily\nduring btree operations. However, nilfs_mdt_save_to_shadow_map()\nassumes i_assoc_inode is already initialized when copying dirty pages\nto the shadow map during GC.\n\nIf NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before\nany btree operation has occurred on the DAT inode, i_assoc_inode is\nNULL leading to a general protection fault.\n\nFix this by calling nilfs_attach_btree_node_cache() on the DAT inode\nin nilfs_dat_read() at mount time, ensuring i_assoc_inode is always\ninitialized before any GC operation can use it.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-24 15:16:32","updated_at":"2026-04-27 20:41:46"},"problem_types":["CWE-476"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"5.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}}],"references":[{"url":"https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e","name":"https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363","name":"https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8","name":"https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084","name":"https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48","name":"https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1","name":"https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31577","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31577","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e897be17a441fa637cd166fc3de1445131e57692 7318e3549518ce8f14776a489d86488d80d7e2c8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e897be17a441fa637cd166fc3de1445131e57692 449ec5fc99f45974525ba9eea16b6670c45cd363 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e897be17a441fa637cd166fc3de1445131e57692 c36e206f302f1ddefed92d09ecbba070e1ae079e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e897be17a441fa637cd166fc3de1445131e57692 41de342278ae025c99cc8d33648773f05e306cf1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map\n\nThe DAT inode's btree node cache (i_assoc_inode) is initialized lazily\nduring btree operations. However, nilfs_mdt_save_to_shadow_map()\nassumes i_assoc_inode is already initialized when copying dirty pages\nto the shadow map during GC.\n\nIf NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before\nany btree operation has occurred on the DAT inode, i_assoc_inode is\nNULL leading to a general protection fault.\n\nFix this by calling nilfs_attach_btree_node_cache() on the DAT inode\nin nilfs_dat_read() at mount time, ensuring i_assoc_inode is always\ninitialized before any GC operation can use it."}],"providerMetadata":{"dateUpdated":"2026-04-27T13:56:24.888Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/7318e3549518ce8f14776a489d86488d80d7e2c8"},{"url":"https://git.kernel.org/stable/c/449ec5fc99f45974525ba9eea16b6670c45cd363"},{"url":"https://git.kernel.org/stable/c/c36e206f302f1ddefed92d09ecbba070e1ae079e"},{"url":"https://git.kernel.org/stable/c/41de342278ae025c99cc8d33648773f05e306cf1"},{"url":"https://git.kernel.org/stable/c/97fb7afec404912d967a7d4715f37742666b3084"},{"url":"https://git.kernel.org/stable/c/4a4e0328edd9e9755843787d28f16dd4165f8b48"}],"title":"nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31577","datePublished":"2026-04-24T14:42:08.879Z","dateReserved":"2026-03-09T15:48:24.119Z","dateUpdated":"2026-04-27T13:56:24.888Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-24 15:16:32","lastModifiedDate":"2026-04-27 20:41:46","problem_types":["CWE-476"],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.136","matchCriteriaId":"14109CEF-714B-4029-A318-97AA58A01833"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.83","matchCriteriaId":"7F0AE5B5-23AC-4DCC-B37A-51CA1DAE7BA8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.24","matchCriteriaId":"8126B8B8-6D0B-4443-86C1-672AEE893555"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"6.19.14","matchCriteriaId":"D6A8A074-BBF4-4803-ABED-519A839435BB"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.0.1","matchCriteriaId":"9B5888AB-7403-4335-89E4-21CC0B48366A"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31577","Ordinal":"1","Title":"nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_","CVE":"CVE-2026-31577","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31577","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map\n\nThe DAT inode's btree node cache (i_assoc_inode) is initialized lazily\nduring btree operations. However, nilfs_mdt_save_to_shadow_map()\nassumes i_assoc_inode is already initialized when copying dirty pages\nto the shadow map during GC.\n\nIf NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before\nany btree operation has occurred on the DAT inode, i_assoc_inode is\nNULL leading to a general protection fault.\n\nFix this by calling nilfs_attach_btree_node_cache() on the DAT inode\nin nilfs_dat_read() at mount time, ensuring i_assoc_inode is always\ninitialized before any GC operation can use it.","Type":"Description","Title":"nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_"}]}}}