{"id":"CVE-2026-89490","state":"PUBLISHED","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.","publishedAt":"2026-09-11T19:43:42.808Z","updatedAt":"2026-10-19T08:47:41.930Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"c28dc3407937aa8f225942538cd585c9b28ea65a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"94569154ba49f5f85645d2019c8e206213d8404e","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"1ae7029823ae4c91664cb32eec7fb8dd5e1a337a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"f9dd5cad8d09110ddff2db1fe756aae93c7552ff","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"c0c165487a2ea5a37ddcdab4259157b7a527129c","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"a63308ab426f3a3c7e33b02c150ea59054620261","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.16","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/dir.c"]}],"references":["https://git.kernel.org/stable/c/c28dc3407937aa8f225942538cd585c9b28ea65a","https://git.kernel.org/stable/c/94569154ba49f5f85645d2019c8e206213d8404e","https://git.kernel.org/stable/c/1ae7029823ae4c91664cb32eec7fb8dd5e1a337a","https://git.kernel.org/stable/c/f9dd5cad8d09110ddff2db1fe756aae93c7552ff","https://git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","https://git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c","https://git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","https://git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89490.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89490","state":"PUBLISHED","datePublished":"2026-09-11T19:43:42.808Z","dateUpdated":"2026-10-19T08:47:41.930Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.713Z"},"containers":{"cna":{"title":"ocfs2: fix readdir position truncation on 32-bit kernels","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"c28dc3407937aa8f225942538cd585c9b28ea65a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"94569154ba49f5f85645d2019c8e206213d8404e","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"1ae7029823ae4c91664cb32eec7fb8dd5e1a337a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"f9dd5cad8d09110ddff2db1fe756aae93c7552ff","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"1001fb3b69a11eaa0dc7c7428f6edfa48b88997a","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"c0c165487a2ea5a37ddcdab4259157b7a527129c","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"b53e2b271eeb6040c2a4a78230c570dc41cdcfa4","versionType":"git"},{"version":"ccd979bdbce9fba8412beb3f1de68a9d0171b12c","status":"affected","lessThan":"a63308ab426f3a3c7e33b02c150ea59054620261","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.16","versionType":"semver"},{"version":"5.10.270","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.221","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.188","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.157","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.109","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.50","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ocfs2/dir.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c28dc3407937aa8f225942538cd585c9b28ea65a"},{"url":"https://git.kernel.org/stable/c/94569154ba49f5f85645d2019c8e206213d8404e"},{"url":"https://git.kernel.org/stable/c/1ae7029823ae4c91664cb32eec7fb8dd5e1a337a"},{"url":"https://git.kernel.org/stable/c/f9dd5cad8d09110ddff2db1fe756aae93c7552ff"},{"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:47:41.930Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"5.10.270"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"5.15.221"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"6.1.188"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"6.6.157"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"6.12.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"6.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.16","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}