{"api_version":"1","generated_at":"2026-09-12T10:56:37+00:00","cve":"CVE-2026-89490","urls":{"html":"https://cve.report/CVE-2026-89490","api":"https://cve.report/api/cve/CVE-2026-89490.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89490","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89490"},"summary":{"title":"ocfs2: fix readdir position truncation on 32-bit kernels","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix readdir position truncation on 32-bit kernels\n\nIn ocfs2_dir_foreach_blk_el(), the directory cookie position is\nrebuilt with\n\n\tctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset;\n\n`ctx->pos` is loff_t (signed 64-bit), while `sb->s_blocksize` is\nunsigned long.  On 32-bit kernels unsigned long is 32-bit, so the mask\n\n\t~(sb->s_blocksize - 1)\n\nis computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB\nblock size).  In the AND expression with the 64-bit `ctx->pos`, that\nunsigned operand is zero-extended to 64 bits per the usual arithmetic\nconversions, yielding 0x00000000fffff000.  The high 32 bits of\n`ctx->pos` are silently cleared, even though directory size is\nallowed to exceed 4 GiB.\n\nWhen readdir() crosses the 4 GiB boundary on a 32-bit kernel the\nposition is reset back into the first 4 GiB block, making the\nre-validation path re-enumerate already-returned dirents indefinitely.\n\nThis is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken\nfor all non-inline directories, so a directory large enough to cross\n4 GiB reaches it.\n\nThis is the same class of bug that commit 3dce5bb82c97 (\"exfat: Fix\nbitwise operation having different size\") fixed in exfat, and the\nfix mirrors the equivalent ext4 fix in this series.  Cast the operand\nto loff_t so the mask is 64-bit before the AND:\n\n\tctx->pos = (ctx->pos & ~((loff_t)sb->s_blocksize - 1)) | offset;\n\n64-bit kernels are unaffected.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:30","updated_at":"2026-09-11 20:19:30"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","name":"https://git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c","name":"https://git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","name":"https://git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261","name":"https://git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89490","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89490","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c 1001fb3b69a11eaa0dc7c7428f6edfa48b88997a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c c0c165487a2ea5a37ddcdab4259157b7a527129c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c b53e2b271eeb6040c2a4a78230c570dc41cdcfa4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ccd979bdbce9fba8412beb3f1de68a9d0171b12c a63308ab426f3a3c7e33b02c150ea59054620261 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 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":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ocfs2/dir.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","status":"affected","version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","versionType":"git"},{"lessThan":"c0c165487a2ea5a37ddcdab4259157b7a527129c","status":"affected","version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","versionType":"git"},{"lessThan":"b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","status":"affected","version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","versionType":"git"},{"lessThan":"a63308ab426f3a3c7e33b02c150ea59054620261","status":"affected","version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ocfs2/dir.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.16"},{"lessThan":"2.6.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","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":"6.12.109","versionStartIncluding":"2.6.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"2.6.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"2.6.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"2.6.16","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix readdir position truncation on 32-bit kernels\n\nIn ocfs2_dir_foreach_blk_el(), the directory cookie position is\nrebuilt with\n\n\tctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset;\n\n`ctx->pos` is loff_t (signed 64-bit), while `sb->s_blocksize` is\nunsigned long.  On 32-bit kernels unsigned long is 32-bit, so the mask\n\n\t~(sb->s_blocksize - 1)\n\nis computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB\nblock size).  In the AND expression with the 64-bit `ctx->pos`, that\nunsigned operand is zero-extended to 64 bits per the usual arithmetic\nconversions, yielding 0x00000000fffff000.  The high 32 bits of\n`ctx->pos` are silently cleared, even though directory size is\nallowed to exceed 4 GiB.\n\nWhen readdir() crosses the 4 GiB boundary on a 32-bit kernel the\nposition is reset back into the first 4 GiB block, making the\nre-validation path re-enumerate already-returned dirents indefinitely.\n\nThis is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken\nfor all non-inline directories, so a directory large enough to cross\n4 GiB reaches it.\n\nThis is the same class of bug that commit 3dce5bb82c97 (\"exfat: Fix\nbitwise operation having different size\") fixed in exfat, and the\nfix mirrors the equivalent ext4 fix in this series.  Cast the operand\nto loff_t so the mask is 64-bit before the AND:\n\n\tctx->pos = (ctx->pos & ~((loff_t)sb->s_blocksize - 1)) | offset;\n\n64-bit kernels are unaffected."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:43:42.808Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a"},{"url":"https://git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c"},{"url":"https://git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4"},{"url":"https://git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261"}],"title":"ocfs2: fix readdir position truncation on 32-bit kernels","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89490","datePublished":"2026-09-11T19:43:42.808Z","dateReserved":"2026-09-11T19:38:34.713Z","dateUpdated":"2026-09-11T19:43:42.808Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:30","lastModifiedDate":"2026-09-11 20:19:30","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89490","Ordinal":"1","Title":"ocfs2: fix readdir position truncation on 32-bit kernels","CVE":"CVE-2026-89490","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89490","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix readdir position truncation on 32-bit kernels\n\nIn ocfs2_dir_foreach_blk_el(), the directory cookie position is\nrebuilt with\n\n\tctx->pos = (ctx->pos & ~(sb->s_blocksize - 1)) | offset;\n\n`ctx->pos` is loff_t (signed 64-bit), while `sb->s_blocksize` is\nunsigned long.  On 32-bit kernels unsigned long is 32-bit, so the mask\n\n\t~(sb->s_blocksize - 1)\n\nis computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB\nblock size).  In the AND expression with the 64-bit `ctx->pos`, that\nunsigned operand is zero-extended to 64 bits per the usual arithmetic\nconversions, yielding 0x00000000fffff000.  The high 32 bits of\n`ctx->pos` are silently cleared, even though directory size is\nallowed to exceed 4 GiB.\n\nWhen readdir() crosses the 4 GiB boundary on a 32-bit kernel the\nposition is reset back into the first 4 GiB block, making the\nre-validation path re-enumerate already-returned dirents indefinitely.\n\nThis is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken\nfor all non-inline directories, so a directory large enough to cross\n4 GiB reaches it.\n\nThis is the same class of bug that commit 3dce5bb82c97 (\"exfat: Fix\nbitwise operation having different size\") fixed in exfat, and the\nfix mirrors the equivalent ext4 fix in this series.  Cast the operand\nto loff_t so the mask is 64-bit before the AND:\n\n\tctx->pos = (ctx->pos & ~((loff_t)sb->s_blocksize - 1)) | offset;\n\n64-bit kernels are unaffected.","Type":"Description","Title":"ocfs2: fix readdir position truncation on 32-bit kernels"}]}}}