{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72162", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.909Z", "datePublished": "2026-08-15T05:53:30.420Z", "dateUpdated": "2026-08-18T06:56:14.095Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-18T06:56:14.095Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec\n\n[BUG]\nOn-disk corruption setting l_next_free_rec to 0 in an inode's embedded\nextent list triggers a UBSAN panic on the next write to that file.\n\n[CAUSE]\nocfs2_sum_rightmost_rec() computes\ni = le16_to_cpu(el->l_next_free_rec) - 1\nand accesses el->l_recs[i] without validating i. When l_next_free_rec\nis 0, i becomes -1; when l_next_free_rec exceeds l_count, i falls\npast the end of the array. Either case violates the\n__counted_by_le(l_count) annotation on l_recs[] and triggers UBSAN.\n\n[FIX]\nValidate the inode's embedded extent list when the inode is read, in\nocfs2_validate_inode_block(): l_count must be non-zero and no larger\nthan the inode block can hold, and l_next_free_rec must not exceed\nl_count. A corrupt list is rejected at read time, before the b-tree\ncode can index l_recs[] out of bounds." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only via local VFS write paths on a mounted OCFS2 volume (write/mmap extending allocation), not from network packet handling or remote protocols; exploitation requires local syscall access to a mounted filesystem.\nAC:L - An attacker can reliably craft on-disk inode metadata (e.g., l_next_free_rec=0) in an OCFS2 image and trigger btree growth with a normal extending write; syzkaller reproduced this deterministically without races or victim-specific timing.\nPR:L - Full exploitation requires mounting a crafted OCFS2 image and writing to it; CAP_SYS_ADMIN for mount/loop setup is obtainable by an unprivileged user via user namespaces, matching the low-privilege bar used for comparable OCFS2 corruption CVEs.\nUI:N - No victim interaction is required when the attacker crafts the corrupt image, mounts it (including via user namespace), and performs the triggering write themselves; no third party must open files or take other actions.\nS:U - Impact is confined to kernel memory/filesystem integrity on the host processing the corrupt OCFS2 metadata; it does not cross VM, container, or IOMMU security boundaries into another authority.\nC:H - The flaw is an out-of-bounds read of extent records from attacker-controlled on-disk fields; even when UBSAN traps, the invalid index access can expose adjacent inode metadata and is classed as information-disclosure-capable memory corruption.\nI:H - The out-of-bounds sum feeds btree growth/shift logic that writes derived cluster counts and tree pointers back to disk, enabling attacker-influenced metadata corruption beyond the immediate read primitive.\nA:H - On UBSAN-enabled kernels the invalid array index triggers a kernel panic on write; even without UBSAN, corrupt btree updates from the bad sum can crash or destabilize the system, satisfying high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/inode.c" ], "versions": [ { "version": "dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8", "lessThan": "671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1", "status": "affected", "versionType": "git" }, { "version": "dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8", "lessThan": "858aa4965ffa8c0d4bb5dd835ac4f1c9a1dcab85", "status": "affected", "versionType": "git" }, { "version": "dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8", "lessThan": "452a8467be8143747292218212671deeb186d2ae", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/ocfs2/inode.c" ], "versions": [ { "version": "2.6.22", "status": "affected" }, { "version": "0", "lessThan": "2.6.22", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1" }, { "url": "https://git.kernel.org/stable/c/858aa4965ffa8c0d4bb5dd835ac4f1c9a1dcab85" }, { "url": "https://git.kernel.org/stable/c/452a8467be8143747292218212671deeb186d2ae" } ], "title": "ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec", "x_generator": { "engine": "bippy-1.2.0" } } } }