{"api_version":"1","generated_at":"2026-09-26T04:26:57+00:00","cve":"CVE-2026-89644","urls":{"html":"https://cve.report/CVE-2026-89644","api":"https://cve.report/api/cve/CVE-2026-89644.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89644","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89644"},"summary":{"title":"btrfs: fix extent map leak in NOCOW direct I/O write","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix extent map leak in NOCOW direct I/O write\n\nbtrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an\nextent map reference that must be dropped on all exit paths.\n\nFor direct writes into a NOCOW range, btrfs_get_blocks_direct_write()\nkeeps using that extent map and asks btrfs_create_dio_extent() to\nallocate the ordered extent. If that fails, for example because\nbtrfs_alloc_ordered_extent() fails, the function returns the error\nwithout dropping the input extent map. The PREALLOC path avoided this by\ndropping the input extent map before replacing it with the newly created\none.\n\nCheck the error from btrfs_create_dio_extent() before replacing the\nmap and drop the input extent map on failure.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:50","updated_at":"2026-09-21 14:17:24"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/3f950867c307c5413d628a153ac44915bd117ffd","name":"https://git.kernel.org/stable/c/3f950867c307c5413d628a153ac44915bd117ffd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b7c873765875645b11503f94c9bae2ca80127375","name":"https://git.kernel.org/stable/c/b7c873765875645b11503f94c9bae2ca80127375","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d","name":"https://git.kernel.org/stable/c/05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2","name":"https://git.kernel.org/stable/c/f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89644","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89644","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af b7c873765875645b11503f94c9bae2ca80127375 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af 05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af 3f950867c307c5413d628a153ac44915bd117ffd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.7","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 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":{"cve_year":"2026","cve_id":"89644","cve":"CVE-2026-89644","epss":"0.001680000","percentile":"0.064510000","score_date":"2026-09-22","updated_at":"2026-09-23 00:06:34"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/btrfs/direct-io.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"b7c873765875645b11503f94c9bae2ca80127375","status":"affected","version":"5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af","versionType":"git"},{"lessThan":"f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2","status":"affected","version":"5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af","versionType":"git"},{"lessThan":"05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d","status":"affected","version":"5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af","versionType":"git"},{"lessThan":"3f950867c307c5413d628a153ac44915bd117ffd","status":"affected","version":"5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/btrfs/direct-io.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.7"},{"lessThan":"4.7","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","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":"6.12.111","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"4.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix extent map leak in NOCOW direct I/O write\n\nbtrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an\nextent map reference that must be dropped on all exit paths.\n\nFor direct writes into a NOCOW range, btrfs_get_blocks_direct_write()\nkeeps using that extent map and asks btrfs_create_dio_extent() to\nallocate the ordered extent. If that fails, for example because\nbtrfs_alloc_ordered_extent() fails, the function returns the error\nwithout dropping the input extent map. The PREALLOC path avoided this by\ndropping the input extent map before replacing it with the newly created\none.\n\nCheck the error from btrfs_create_dio_extent() before replacing the\nmap and drop the input extent map on failure."}],"providerMetadata":{"dateUpdated":"2026-09-21T13:14:39.048Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/b7c873765875645b11503f94c9bae2ca80127375"},{"url":"https://git.kernel.org/stable/c/f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2"},{"url":"https://git.kernel.org/stable/c/05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d"},{"url":"https://git.kernel.org/stable/c/3f950867c307c5413d628a153ac44915bd117ffd"}],"title":"btrfs: fix extent map leak in NOCOW direct I/O write","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89644","datePublished":"2026-09-11T19:45:36.268Z","dateReserved":"2026-09-11T19:38:34.741Z","dateUpdated":"2026-09-21T13:14:39.048Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:50","lastModifiedDate":"2026-09-21 14:17:24","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89644","Ordinal":"1","Title":"btrfs: fix extent map leak in NOCOW direct I/O write","CVE":"CVE-2026-89644","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89644","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix extent map leak in NOCOW direct I/O write\n\nbtrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an\nextent map reference that must be dropped on all exit paths.\n\nFor direct writes into a NOCOW range, btrfs_get_blocks_direct_write()\nkeeps using that extent map and asks btrfs_create_dio_extent() to\nallocate the ordered extent. If that fails, for example because\nbtrfs_alloc_ordered_extent() fails, the function returns the error\nwithout dropping the input extent map. The PREALLOC path avoided this by\ndropping the input extent map before replacing it with the newly created\none.\n\nCheck the error from btrfs_create_dio_extent() before replacing the\nmap and drop the input extent map on failure.","Type":"Description","Title":"btrfs: fix extent map leak in NOCOW direct I/O write"}]}}}