{"id":"CVE-2026-92501","revision":null,"records":[{"revision":"81a3f20a4d614e788dd20f008d0d902f","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-92501","aliases":[],"title":"ext4: drain in-flight DIO before buffered write fallback","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: drain in-flight DIO before buffered write fallback\n\ngeneric/746 started failing intermittently on ext3 (no-extent inodes).\nThe test triggers 'Page cache invalidation failure on direct I/O'\nwarnings and subsequent fsync returns -EIO. Adding a 50ms delay\nbetween ext4_buffered_write_iter() and filemap_write_and_wait_range()\nin ext4_dio_write_iter() makes the race almost always reproducible.\n\nOn no-extent inodes, DIO writes to holes cannot use unwritten extents,\nso ext4_iomap_alloc() leaves m_flags=0 and ext4_map_blocks() returns 0.\nThe iomap layer then returns -ENOTBLK, causing fallback to buffered I/O.\n\nThe fallback path in ext4_dio_write_iter() calls\next4_buffered_write_iter() which dirties pages, then does flush and\ninvalidate. However, there's an unprotected window between\next4_buffered_write_iter() returning (with inode lock released) and\nthe subsequent flush+invalidate.\n\nConcurrent async DIO completions from other threads can run\nkiocb_invalidate_post_direct_write() during this window. If pages have\nbeen re-dirtied, post-invalidation finds dirty pages and triggers the\nwarning, setting -EIO in the error sequence.\n\nConsider a file with two 4k extents: [hole][written]. Thread A does\nDIO to the written extent, while thread B does DIO spanning both:\n\n kworker A (4k DIO, allocated block) kworker B (8k DIO, fallback)\n ----------------------------------- ----------------------------\n inode_lock_shared() inode_lock_shared()\n iomap_dio_rw(): iomap_dio_rw():\n kiocb_invalidate_pages -> clean iomap_begin -> -ENOTBLK\n submit_bio (async) dio->size = 0\n inode_unlock_shared() inode_unlock_shared()\n\n [bio pending in block layer] /* fallback: lock released */\n ext4_buffered_write_iter()\n inode_lock(exclusive)\n generic_perform_write()\n -> dirty pages [0, 8k]\n inode_unlock(exclusive)\n\n /* pages dirty, no lock */\n [bio completes] filemap_write_and_wait_range()\n iomap_dio_complete() -> flush dirty pages\n kiocb_invalidate_post_direct_write() invalidate_mapping_pages()\n invalidate_inode_pages2_range()\n -> finds dirty page!\n -> dio_warn_stale_pagecache()\n -> errseq_set(-EIO)\n\nThis issue can be triggered through normal I/O paths, not just\nintentionally overlapping DIO writes from userspace. For example,\ngeneric/746 uses a loop device where multiple kworkers issue concurrent\nI/O to the backing file. Additionally, when block_size < folio_size,\nnon-overlapping DIO writes that share a large folio can also trigger\nthe race.\n\nAdd inode_dio_wait() in ext4_buffered_write_iter() before\next4_write_checks() to drain all in-flight DIO. This ensures that\nall DIO clears existing pages before submitting IO (via\nkiocb_invalidate_pages()), all BIO waits for all DIO to complete\n(via inode_dio_wait()), and ext4_write_checks() observes the inode\nsize after all completed DIO so that ext4_block_zero_eof() does not\nrace with in-flight DIO, thus eliminating the race.","state":0,"publishedAt":"2026-09-17T16:10:14.753+00:00","modifiedAt":"2026-10-19T09:04:07.25+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/ext4/file.c\"\n ],\n \"versions\": [\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"fd7e0dab20837b9ea1eeef7c26f78ace8ac8258c\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"f0af3ae09fb72382da1a5371bf6761b0264668e4\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"7341e234927ff215f1d5d0bcfe04b74f53af378d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"74eee4ff9698a65b2e6e15dac0e50d6526ad5f20\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"d47cdadd6e49023f7ee248048463807f1214f1ee\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"4e4e3eec506247c8f8bd8aaa1eb25e67016681a5\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"9fd3ffc3c51c9deaba99bd7b338fff2d08f52416\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"378f32bab3714f04c4e0c3aee4129f6703805550\",\n \"lessThan\": \"15cdefd0c0522f9d5e12d947fa04f4c11649b699\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/ext4/file.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.5\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.5\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.270\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.221\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.188\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.157\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.110\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.52\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.6\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/fd7e0dab20837b9ea1eeef7c26f78ace8ac8258c","https://git.kernel.org/stable/c/f0af3ae09fb72382da1a5371bf6761b0264668e4","https://git.kernel.org/stable/c/7341e234927ff215f1d5d0bcfe04b74f53af378d","https://git.kernel.org/stable/c/74eee4ff9698a65b2e6e15dac0e50d6526ad5f20","https://git.kernel.org/stable/c/d47cdadd6e49023f7ee248048463807f1214f1ee","https://git.kernel.org/stable/c/4e4e3eec506247c8f8bd8aaa1eb25e67016681a5","https://git.kernel.org/stable/c/9fd3ffc3c51c9deaba99bd7b338fff2d08f52416","https://git.kernel.org/stable/c/15cdefd0c0522f9d5e12d947fa04f4c11649b699"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-92501","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-92501","identifiers":["CVE-2026-92501"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T02:08:49.7164208+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-09T02:08:49.7164208+00:00","lastSuccessAt":"2026-11-09T02:08:49.9138759+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.9138791+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-24e6fde7b744113daefb8f6135035fb8a5c69c9617c9c0d40574a0376532ffd3-2c51878ad7143765cecd1875e45367b3d7bc82d957efe97a97e8abc47229db89","complete":true,"records":421276,"lastAttemptAt":"2026-11-09T02:08:48.6040206+00:00","lastSuccessAt":"2026-11-09T02:08:48.5948774+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:48.6040206+00:00","snapshotPublishedAt":"2026-11-09T01:29:01+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-3c8e547b28ad4f0fa34b0d9a3442b37e","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T02:21:06.332251+00:00","lastSuccessAt":"2026-11-09T02:21:06.328+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:21:06.328+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13634,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-09T02:08:49.7164208+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T02:08:49.7164208+00:00","lastSuccessAt":"2026-11-09T02:08:49.9145991+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.9145992+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-5a44a451442747cb81d83104fe1e7771","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T02:08:52.2785198+00:00","lastSuccessAt":"2026-11-09T02:08:52.274+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:52.274+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-09T02:08:49.2635464+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.2635464+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-09T02:08:48.7750517+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:48.7750517+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-3b1150af6d7ada2c07356cbab4ead5224c1485027890f71c71d0742cddf0b9e8","complete":true,"records":3055,"lastAttemptAt":"2026-11-09T02:08:49.6317268+00:00","lastSuccessAt":"2026-11-09T00:02:23.4330288+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.6317268+00:00","snapshotPublishedAt":"2026-11-08T23:17:54+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-09T02:08:49.149268+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-09T02:08:49.149268+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}