{"api_version":"1","generated_at":"2026-09-18T04:51:40+00:00","cve":"CVE-2026-92500","urls":{"html":"https://cve.report/CVE-2026-92500","api":"https://cve.report/api/cve/CVE-2026-92500.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-92500","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-92500"},"summary":{"title":"ext4: use fsdata to track inline data write state and fix race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: use fsdata to track inline data write state and fix race\n\nInstead of checking the live inode state (ext4_has_inline_data(inode)\nand ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the\nwrite_end handlers, use the fsdata parameter of the address space\noperations to explicitly pass down the state in which write_begin\nprepared the write.\n\nA concurrent thread (such as ext4_page_mkwrite()) can convert the\ninline data to an extent between write_begin and write_end. If this\nhappens, the write_end handlers would previously miss the inline\nwrite_end path and fall through to extent-based write_end logic.\nHowever, since block buffers were never allocated in write_begin,\nthis resulted in NULL pointer dereferences or data loss because\nfolio_buffers(folio) was NULL.\n\nDefine EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating\nfsdata as bitwise flags rather than mutually exclusive enums to keep\nstates of the write path independent. Communicate this state via\nfsdata:\n1) ext4_write_begin() and ext4_da_write_begin() set the\n   EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline\n   write is successfully prepared.\n2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit\n   to safely handle VFS retries (where generic_perform_write() bypasses\n   the fsdata initialization on its retry jump).\n3) The write_end handlers perform a bitwise AND to check if the\n   EXT4_WRITE_DATA_INLINE bit is set and invoke the inline write_end\n   helper accordingly.\n\nFurthermore, during a buffered write, ext4_write_inline_data_end()\nacquires the xattr lock after preparing the write. If a concurrent\npage fault (ext4_page_mkwrite()) converts the inline data to an extent\nafter the write_end handlers check the state but before\next4_write_inline_data_end() acquires the xattr write lock, the\nsubsequent check will trigger a kernel panic via\nBUG_ON(!ext4_has_inline_data(inode)).\n\nTo keep git history working and bisectability clean, replace the\nBUG_ON check in ext4_write_inline_data_end() with a graceful error-\nhandling retry path in this same commit. If the inline data is cleared\nafter locking the xattr, we safely release all resources (releasing\niloc.bh, unlocking/putting the folio, stopping the active journal\ntransaction handle) and return 0 (VFS retry) to let the generic write\npath retry the operation safely.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:17:52","updated_at":"2026-09-17 17:17:52"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/439aedfd7ae868d1d7b4930afe66091cb979cd5c","name":"https://git.kernel.org/stable/c/439aedfd7ae868d1d7b4930afe66091cb979cd5c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7edbb323bab2b2a609016014caafdb651c898249","name":"https://git.kernel.org/stable/c/7edbb323bab2b2a609016014caafdb651c898249","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bd8d74bd46d09905164255b8635fa58b45f41068","name":"https://git.kernel.org/stable/c/bd8d74bd46d09905164255b8635fa58b45f41068","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-92500","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92500","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb bd8d74bd46d09905164255b8635fa58b45f41068 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb 439aedfd7ae868d1d7b4930afe66091cb979cd5c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb 7edbb323bab2b2a609016014caafdb651c898249 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.8","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.8 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * 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":["fs/ext4/ext4.h","fs/ext4/inline.c","fs/ext4/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"bd8d74bd46d09905164255b8635fa58b45f41068","status":"affected","version":"3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb","versionType":"git"},{"lessThan":"439aedfd7ae868d1d7b4930afe66091cb979cd5c","status":"affected","version":"3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb","versionType":"git"},{"lessThan":"7edbb323bab2b2a609016014caafdb651c898249","status":"affected","version":"3fdcfb668fd78ec92d9bc2daddf1d41e2a8a30bb","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ext4/ext4.h","fs/ext4/inline.c","fs/ext4/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.8"},{"lessThan":"3.8","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"3.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"3.8","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"3.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: use fsdata to track inline data write state and fix race\n\nInstead of checking the live inode state (ext4_has_inline_data(inode)\nand ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the\nwrite_end handlers, use the fsdata parameter of the address space\noperations to explicitly pass down the state in which write_begin\nprepared the write.\n\nA concurrent thread (such as ext4_page_mkwrite()) can convert the\ninline data to an extent between write_begin and write_end. If this\nhappens, the write_end handlers would previously miss the inline\nwrite_end path and fall through to extent-based write_end logic.\nHowever, since block buffers were never allocated in write_begin,\nthis resulted in NULL pointer dereferences or data loss because\nfolio_buffers(folio) was NULL.\n\nDefine EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating\nfsdata as bitwise flags rather than mutually exclusive enums to keep\nstates of the write path independent. Communicate this state via\nfsdata:\n1) ext4_write_begin() and ext4_da_write_begin() set the\n   EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline\n   write is successfully prepared.\n2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit\n   to safely handle VFS retries (where generic_perform_write() bypasses\n   the fsdata initialization on its retry jump).\n3) The write_end handlers perform a bitwise AND to check if the\n   EXT4_WRITE_DATA_INLINE bit is set and invoke the inline write_end\n   helper accordingly.\n\nFurthermore, during a buffered write, ext4_write_inline_data_end()\nacquires the xattr lock after preparing the write. If a concurrent\npage fault (ext4_page_mkwrite()) converts the inline data to an extent\nafter the write_end handlers check the state but before\next4_write_inline_data_end() acquires the xattr write lock, the\nsubsequent check will trigger a kernel panic via\nBUG_ON(!ext4_has_inline_data(inode)).\n\nTo keep git history working and bisectability clean, replace the\nBUG_ON check in ext4_write_inline_data_end() with a graceful error-\nhandling retry path in this same commit. If the inline data is cleared\nafter locking the xattr, we safely release all resources (releasing\niloc.bh, unlocking/putting the folio, stopping the active journal\ntransaction handle) and return 0 (VFS retry) to let the generic write\npath retry the operation safely."}],"providerMetadata":{"dateUpdated":"2026-09-17T16:10:14.073Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/bd8d74bd46d09905164255b8635fa58b45f41068"},{"url":"https://git.kernel.org/stable/c/439aedfd7ae868d1d7b4930afe66091cb979cd5c"},{"url":"https://git.kernel.org/stable/c/7edbb323bab2b2a609016014caafdb651c898249"}],"title":"ext4: use fsdata to track inline data write state and fix race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-92500","datePublished":"2026-09-17T16:10:14.073Z","dateReserved":"2026-09-16T12:21:13.871Z","dateUpdated":"2026-09-17T16:10:14.073Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:17:52","lastModifiedDate":"2026-09-17 17:17:52","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"92500","Ordinal":"1","Title":"ext4: use fsdata to track inline data write state and fix race","CVE":"CVE-2026-92500","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"92500","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: use fsdata to track inline data write state and fix race\n\nInstead of checking the live inode state (ext4_has_inline_data(inode)\nand ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) in the\nwrite_end handlers, use the fsdata parameter of the address space\noperations to explicitly pass down the state in which write_begin\nprepared the write.\n\nA concurrent thread (such as ext4_page_mkwrite()) can convert the\ninline data to an extent between write_begin and write_end. If this\nhappens, the write_end handlers would previously miss the inline\nwrite_end path and fall through to extent-based write_end logic.\nHowever, since block buffers were never allocated in write_begin,\nthis resulted in NULL pointer dereferences or data loss because\nfolio_buffers(folio) was NULL.\n\nDefine EXT4_WRITE_DATA_INLINE (4) as a bit flag (Bit 2), treating\nfsdata as bitwise flags rather than mutually exclusive enums to keep\nstates of the write path independent. Communicate this state via\nfsdata:\n1) ext4_write_begin() and ext4_da_write_begin() set the\n   EXT4_WRITE_DATA_INLINE bit in *fsdata via bitwise OR when an inline\n   write is successfully prepared.\n2) On entry, ext4_write_begin() clears the EXT4_WRITE_DATA_INLINE bit\n   to safely handle VFS retries (where generic_perform_write() bypasses\n   the fsdata initialization on its retry jump).\n3) The write_end handlers perform a bitwise AND to check if the\n   EXT4_WRITE_DATA_INLINE bit is set and invoke the inline write_end\n   helper accordingly.\n\nFurthermore, during a buffered write, ext4_write_inline_data_end()\nacquires the xattr lock after preparing the write. If a concurrent\npage fault (ext4_page_mkwrite()) converts the inline data to an extent\nafter the write_end handlers check the state but before\next4_write_inline_data_end() acquires the xattr write lock, the\nsubsequent check will trigger a kernel panic via\nBUG_ON(!ext4_has_inline_data(inode)).\n\nTo keep git history working and bisectability clean, replace the\nBUG_ON check in ext4_write_inline_data_end() with a graceful error-\nhandling retry path in this same commit. If the inline data is cleared\nafter locking the xattr, we safely release all resources (releasing\niloc.bh, unlocking/putting the folio, stopping the active journal\ntransaction handle) and return 0 (VFS retry) to let the generic write\npath retry the operation safely.","Type":"Description","Title":"ext4: use fsdata to track inline data write state and fix race"}]}}}