{"id":"CVE-2026-89723","title":"nilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation\n\nShuangpeng Bai reported that KASAN detected a slab-out-of-bounds error\nin nilfs_direct_propag…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 39005fd1ce654ffdecacddc406b9a038efe606e6","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < bf49e6f6ddc12445a0330708b365de6458085980","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 5d3783c451a546373662ee11ec17019273e68034","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 448636c745a3f3b8582a0b8ce718c890a11c0fa9","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 28362e8ce51377afdec1782e661e808328a10514","Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 45662dedb8f272ef7f16e69f13424c4bd0399240","Linux 2.6.30"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:51:35.942Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89723","references":[{"url":"https://git.kernel.org/stable/c/39005fd1ce654ffdecacddc406b9a038efe606e6"},{"url":"https://git.kernel.org/stable/c/bf49e6f6ddc12445a0330708b365de6458085980"},{"url":"https://git.kernel.org/stable/c/4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d"},{"url":"https://git.kernel.org/stable/c/b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf"},{"url":"https://git.kernel.org/stable/c/5d3783c451a546373662ee11ec17019273e68034"},{"url":"https://git.kernel.org/stable/c/448636c745a3f3b8582a0b8ce718c890a11c0fa9"},{"url":"https://git.kernel.org/stable/c/28362e8ce51377afdec1782e661e808328a10514"},{"url":"https://git.kernel.org/stable/c/45662dedb8f272ef7f16e69f13424c4bd0399240"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89723.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89723"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532191"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89723"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89723"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89723.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00169,"epssPercentile":0.06193,"scores":{"cna":7.8,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.449Z","slug":"CVE-2026-89723","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation\n\nShuangpeng Bai reported that KASAN detected a slab-out-of-bounds error\nin nilfs_direct_propagate() during testing.\n\nAnalysis revealed that after truncating a file, a node block immediately\nbelow the B-tree root was not deleted.  Instead, it remained in the B-tree\nnode cache in a dirty state.  The log writer subsequently detected this\nblock and incorrectly invoked nilfs_direct_propagate() on it, which is\ndesigned to handle only data blocks in direct mapping.\n\nB-tree nodes in the cache are managed by virtual block numbers, and their\nlogical keys typically exceed the range expected by direct mapping.\nConsequently, processing such a node as a direct mapping entry triggers\na slab-out-of-bounds access.\n\nThe root cause is that when a B-tree mapping collapses into a direct\nmapping during truncation, an intermediate node block pointed to by the\nroot node is left behind as garbage instead of being explicitly deleted.\n\nThis resolves the issue by adding a nilfs_btree_discard() operation\nto delete the remaining intermediate node block during the conversion.\nA 'deform' flag is added to the bop_delete interface to explicitly signal\nthat the deletion is part of a mapping transformation.  This allows the\nB-tree mapping implementation to perform the necessary cleanup and\ndiscarding of the residual node structure that would be otherwise be left\norphaned after the transition.\n\n## Affected\n\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 39005fd1ce654ffdecacddc406b9a038efe606e6`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < bf49e6f6ddc12445a0330708b365de6458085980`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 4a1bb1f9f24a935c9b3f4fbf98012fa6d4ad826d`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < b313edfbc0c2a60f7ce09b2e81ee71909ab8ddaf`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 5d3783c451a546373662ee11ec17019273e68034`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 448636c745a3f3b8582a0b8ce718c890a11c0fa9`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 28362e8ce51377afdec1782e661e808328a10514`\n- `Linux >= 36a580eb489f54d81a0534974962e732a314b999 < 45662dedb8f272ef7f16e69f13424c4bd0399240`\n- `Linux 2.6.30`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89723.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224596,"id":"CVE-2026-89723","ts":1792401426102,"field":"cvss","old":"5.5","new":"7.8"},{"seq":224595,"id":"CVE-2026-89723","ts":1792401426102,"field":"severity","old":"medium","new":"high"},{"seq":208916,"id":"CVE-2026-89723","ts":1790062284429,"field":"cvss","old":"7.8","new":"5.5"},{"seq":208915,"id":"CVE-2026-89723","ts":1790062284429,"field":"severity","old":"high","new":"medium"},{"seq":197700,"id":"CVE-2026-89723","ts":1789384318464,"field":"cvss","old":"6.5","new":"7.8"},{"seq":197699,"id":"CVE-2026-89723","ts":1789384318464,"field":"severity","old":"medium","new":"high"},{"seq":183335,"id":"CVE-2026-89723","ts":1789356674915,"field":"cvss","old":"7.8","new":"6.5"},{"seq":183334,"id":"CVE-2026-89723","ts":1789356674915,"field":"severity","old":"high","new":"medium"},{"seq":153608,"id":"CVE-2026-89723","ts":1789285351485,"field":"cvss","old":null,"new":"7.8"},{"seq":153607,"id":"CVE-2026-89723","ts":1789285351485,"field":"severity","old":"none","new":"high"},{"seq":147598,"id":"CVE-2026-89723","ts":1789270211540,"field":"cvss","old":null,"new":"6.5"},{"seq":147597,"id":"CVE-2026-89723","ts":1789270211540,"field":"severity","old":"none","new":"medium"},{"seq":109356,"id":"CVE-2026-89723","ts":1789183731591,"field":"cvss","old":null,"new":"6.5"},{"seq":109355,"id":"CVE-2026-89723","ts":1789183731591,"field":"severity","old":"none","new":"medium"}]}