CVE-2026-72162 (GCVE-0-2026-72162)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:53 – Updated: 2026-08-18 06:56
VLAI
Title
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
Summary
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec [BUG] On-disk corruption setting l_next_free_rec to 0 in an inode's embedded extent list triggers a UBSAN panic on the next write to that file. [CAUSE] ocfs2_sum_rightmost_rec() computes i = le16_to_cpu(el->l_next_free_rec) - 1 and accesses el->l_recs[i] without validating i. When l_next_free_rec is 0, i becomes -1; when l_next_free_rec exceeds l_count, i falls past the end of the array. Either case violates the __counted_by_le(l_count) annotation on l_recs[] and triggers UBSAN. [FIX] Validate the inode's embedded extent list when the inode is read, in ocfs2_validate_inode_block(): l_count must be non-zero and no larger than the inode block can hold, and l_next_free_rec must not exceed l_count. A corrupt list is rejected at read time, before the b-tree code can index l_recs[] out of bounds.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8 , < 671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1 (git)
Affected: dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8 , < 858aa4965ffa8c0d4bb5dd835ac4f1c9a1dcab85 (git)
Affected: dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8 , < 452a8467be8143747292218212671deeb186d2ae (git)
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Linux Linux Affected: 2.6.22
Unaffected: 0 , < 2.6.22 (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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      "affected": [
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          "product": "Linux",
          "programFiles": [
            "fs/ocfs2/inode.c"
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          "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\u0027s 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-\u003el_next_free_rec) - 1\nand accesses el-\u003el_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\u0027s 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."
        }
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "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."
            }
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      "providerMetadata": {
        "dateUpdated": "2026-08-18T06:56:14.095Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1"
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          "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",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72162",
    "datePublished": "2026-08-15T05:53:30.420Z",
    "dateReserved": "2026-08-09T03:40:39.909Z",
    "dateUpdated": "2026-08-18T06:56:14.095Z",
    "state": "PUBLISHED"
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      "initial_release_date": "2026-08-23T14:45:56.000Z",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
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      "title": "ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec",
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      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72162\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:21:34.117\",\"lastModified\":\"2026-08-18T07:16:53.017\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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\u0027s 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-\u003el_next_free_rec) - 1\\nand accesses el-\u003el_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\u0027s 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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ocfs2/inode.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8\",\"lessThan\":\"671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8\",\"lessThan\":\"858aa4965ffa8c0d4bb5dd835ac4f1c9a1dcab85\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"dcd0538ff4e854fa9d7f4630b359ca8fdb5cb5a8\",\"lessThan\":\"452a8467be8143747292218212671deeb186d2ae\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/ocfs2/inode.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.22\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.22\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"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\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/452a8467be8143747292218212671deeb186d2ae\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/671889c553ea55e2da6a4f3b15f4c0fa40f2f0d1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/858aa4965ffa8c0d4bb5dd835ac4f1c9a1dcab85\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
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      "current_release_date": "2026-08-18T14:32:42+00:00",
      "cve": "CVE-2026-72162",
      "id": "CVE-2026-72162",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72162.json",
      "version": "3"
    }
  }
}



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