Vulnerability-Lookup

CVE-2026-89786 (GCVE-0-2026-89786)

Vulnerability from cvelistv5 – Published: 2026-09-16 08:48 – Updated: 2026-09-16 14:38

Title

ext4: fix out-of-bounds read in ext4_read_inline_dir()

Summary

In the Linux kernel, the following vulnerability has been resolved: ext4: fix out-of-bounds read in ext4_read_inline_dir() ext4_read_inline_dir() can read a dirent header past the end of its inline buffer, triggering a slab-out-of-bounds read during getdents64(): BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry Read of size 2 at addr ffff88800f3dd23c by task exploit/148 ... __ext4_check_dir_entry ext4_read_inline_dir iterate_dir The dirent payload lives in a buffer of exactly inline_size bytes: dir_buf = kmalloc(inline_size, GFP_NOFS); but iteration runs in a position space extra_offset bytes larger (extra_size = extra_offset + inline_size) so the synthetic "." and ".." land at their block-dir offsets. A dirent is formed at "dir_buf + pos - extra_offset", yet the ext4_check_dir_entry() length argument uses the larger extra_size. A position whose dirent header would extend past extra_size is therefore accepted, and the rescan loop's rec_len probe and ext4_check_dir_entry() dereference de->rec_len before the entry is rejected. Reject a position whose minimum-size dirent header would not fit within extra_size before forming de, in both the rescan and main loops, and pass inline_size rather than extra_size to ext4_check_dir_entry() so the length check matches the physical buffer.

Severity

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Assigner

Linux mitre root

References

7 references

URL	Tags
https://git.kernel.org/stable/c/d1e7c186555ad6555…
https://git.kernel.org/stable/c/5fd20d4e50dd6e460…
https://git.kernel.org/stable/c/1a1dea633b724a1c0…
https://git.kernel.org/stable/c/b060861f662d4826d…
https://git.kernel.org/stable/c/6702c7da86d8cdb88…
https://git.kernel.org/stable/c/36bf17bb90cdf7a62…
https://git.kernel.org/stable/c/9333cc809f0a89e00…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < d1e7c186555ad65554fd2f2b02f5a539aa35ae48 (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < 5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < 1a1dea633b724a1c042dbcdb1fed27f410916688 (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < b060861f662d4826dc700a1c3584243bb3474cfe (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < 6702c7da86d8cdb88d0fc57166286e115ffeb8c0 (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < 36bf17bb90cdf7a623499b624b05acde4d2feef5 (git) Affected: c4d8b0235aa98f8c26bf94d308be3fdd24154572 , < 9333cc809f0a89e001b814155a6cb8903a6274df (git)	guessed
Linux	Linux	Affected: 3.10 Unaffected: 0 , < 3.10 (semver) Unaffected: 5.15.221 , ≤ 5.15.* (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.110 , ≤ 6.12.* (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/inline.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "1a1dea633b724a1c042dbcdb1fed27f410916688",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "b060861f662d4826dc700a1c3584243bb3474cfe",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "6702c7da86d8cdb88d0fc57166286e115ffeb8c0",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "36bf17bb90cdf7a623499b624b05acde4d2feef5",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "9333cc809f0a89e001b814155a6cb8903a6274df",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            }
          ]
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        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.10"
            },
            {
              "lessThan": "3.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "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": "5.15.221",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.188",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                {
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                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "3.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix out-of-bounds read in ext4_read_inline_dir()\n\next4_read_inline_dir() can read a dirent header past the end of its inline\nbuffer, triggering a slab-out-of-bounds read during getdents64():\n\n  BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry\n  Read of size 2 at addr ffff88800f3dd23c by task exploit/148\n   ...\n   __ext4_check_dir_entry\n   ext4_read_inline_dir\n   iterate_dir\n\nThe dirent payload lives in a buffer of exactly inline_size bytes:\n\n\tdir_buf = kmalloc(inline_size, GFP_NOFS);\n\nbut iteration runs in a position space extra_offset bytes larger\n(extra_size = extra_offset + inline_size) so the synthetic \".\" and \"..\"\nland at their block-dir offsets. A dirent is formed at \"dir_buf + pos -\nextra_offset\", yet the ext4_check_dir_entry() length argument uses the\nlarger extra_size. A position whose dirent header would extend past\nextra_size is therefore accepted, and the rescan loop\u0027s rec_len probe and\next4_check_dir_entry() dereference de-\u003erec_len before the entry is rejected.\n\nReject a position whose minimum-size dirent header would not fit within\nextra_size before forming de, in both the rescan and main loops, and pass\ninline_size rather than extra_size to ext4_check_dir_entry() so the length\ncheck matches the physical buffer."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The slab OOB is in ext4_read_inline_dir(), reached from getdents64 via iterate_dir\u2192ext4_readdir. nfsd_readdir does vfs_llseek plus iterate_dir, and ksmbd QUERY_DIRECTORY also calls iterate_dir, so a remote NFS/SMB client can trigger the same path on an ext4-backed export.\nAC:L - A crafted inline directory with attacker-controlled rec_len values (or a seek/NFS cookie that lands ctx-\u003epos near extra_size) deterministically forms a dirent past kmalloc(inline_size) and dereferences de-\u003erec_len. No race or attacker-uncontrollable heap layout is required.\nPR:N - READDIR on a guest/anonymous ksmbd share or AUTH_SYS NFS export needs no host account or capability. Automount of a malicious volume by udisks2/systemd also requires no attacker privileges on the victim.\nUI:N - Once the crafted or inline-data ext4 volume is exported or automounted, the attacker alone issues NFS/SMB READDIR or local getdents64. No separate victim must open a file or confirm a dialog at attack time.\nS:U - The out-of-bounds read and any resulting kernel crash stay within the host kernel\u0027s security authority. This is not a VM escape, IOMMU/DMA bypass, or other cross-boundary breakout.\nC:H - ext4_check_dir_entry over-reads de-\u003erec_len and adjacent dirent fields past the inline kmalloc buffer. If the inflated extra_size bound lets the check pass, dir_emit copies de-\u003ename for up to 255 bytes of adjacent kernel heap into the getdents/NFS/SMB reply.\nI:N - The defect is an over-read on the readdir path only. ext4_read_inline_dir does not write the over-read dirent, and there is no out-of-bounds write, type confusion, or control-flow hijack primitive.\nA:H - KASAN reports a slab-out-of-bounds read in __ext4_check_dir_entry. An over-read that reaches unmapped slab or guard pages oopses or panics the kernel, and the attacker can repeat READDIR/getdents against the crafted directory."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:38:36.340Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48"
        },
        {
          "url": "https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f"
        },
        {
          "url": "https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688"
        },
        {
          "url": "https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe"
        },
        {
          "url": "https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0"
        },
        {
          "url": "https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5"
        },
        {
          "url": "https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df"
        }
      ],
      "title": "ext4: fix out-of-bounds read in ext4_read_inline_dir()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89786",
    "datePublished": "2026-09-16T08:48:23.730Z",
    "dateReserved": "2026-09-11T19:38:34.766Z",
    "dateUpdated": "2026-09-16T14:38:36.340Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-89786",
      "date": "2026-09-16",
      "epss": "0.00205",
      "percentile": "0.10809"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-89786\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-16T09:17:09.330\",\"lastModified\":\"2026-09-16T15:18:08.860\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\next4: fix out-of-bounds read in ext4_read_inline_dir()\\n\\next4_read_inline_dir() can read a dirent header past the end of its inline\\nbuffer, triggering a slab-out-of-bounds read during getdents64():\\n\\n  BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry\\n  Read of size 2 at addr ffff88800f3dd23c by task exploit/148\\n   ...\\n   __ext4_check_dir_entry\\n   ext4_read_inline_dir\\n   iterate_dir\\n\\nThe dirent payload lives in a buffer of exactly inline_size bytes:\\n\\n\\tdir_buf = kmalloc(inline_size, GFP_NOFS);\\n\\nbut iteration runs in a position space extra_offset bytes larger\\n(extra_size = extra_offset + inline_size) so the synthetic \\\".\\\" and \\\"..\\\"\\nland at their block-dir offsets. A dirent is formed at \\\"dir_buf + pos -\\nextra_offset\\\", yet the ext4_check_dir_entry() length argument uses the\\nlarger extra_size. A position whose dirent header would extend past\\nextra_size is therefore accepted, and the rescan loop\u0027s rec_len probe and\\next4_check_dir_entry() dereference de-\u003erec_len before the entry is rejected.\\n\\nReject a position whose minimum-size dirent header would not fit within\\nextra_size before forming de, in both the rescan and main loops, and pass\\ninline_size rather than extra_size to ext4_check_dir_entry() so the length\\ncheck matches the physical buffer.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/ext4/inline.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"d1e7c186555ad65554fd2f2b02f5a539aa35ae48\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"1a1dea633b724a1c042dbcdb1fed27f410916688\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"b060861f662d4826dc700a1c3584243bb3474cfe\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"6702c7da86d8cdb88d0fc57166286e115ffeb8c0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"36bf17bb90cdf7a623499b624b05acde4d2feef5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"c4d8b0235aa98f8c26bf94d308be3fdd24154572\",\"lessThan\":\"9333cc809f0a89e001b814155a6cb8903a6274df\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/ext4/inline.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.10\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.10\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.221\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.188\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.157\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.110\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.52\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.6\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"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:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H\",\"baseScore\":9.1,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.2}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}

FKIE_CVE-2026-89786

Vulnerability from fkie_nvd - Published: 2026-09-16 09:17 - Updated: 2026-09-16 15:18

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Summary

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/inline.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d1e7c186555ad65554fd2f2b02f5a539aa35ae48",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "1a1dea633b724a1c042dbcdb1fed27f410916688",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "b060861f662d4826dc700a1c3584243bb3474cfe",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "6702c7da86d8cdb88d0fc57166286e115ffeb8c0",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "36bf17bb90cdf7a623499b624b05acde4d2feef5",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            },
            {
              "lessThan": "9333cc809f0a89e001b814155a6cb8903a6274df",
              "status": "affected",
              "version": "c4d8b0235aa98f8c26bf94d308be3fdd24154572",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ext4/inline.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.10"
            },
            {
              "lessThan": "3.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix out-of-bounds read in ext4_read_inline_dir()\n\next4_read_inline_dir() can read a dirent header past the end of its inline\nbuffer, triggering a slab-out-of-bounds read during getdents64():\n\n  BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry\n  Read of size 2 at addr ffff88800f3dd23c by task exploit/148\n   ...\n   __ext4_check_dir_entry\n   ext4_read_inline_dir\n   iterate_dir\n\nThe dirent payload lives in a buffer of exactly inline_size bytes:\n\n\tdir_buf = kmalloc(inline_size, GFP_NOFS);\n\nbut iteration runs in a position space extra_offset bytes larger\n(extra_size = extra_offset + inline_size) so the synthetic \".\" and \"..\"\nland at their block-dir offsets. A dirent is formed at \"dir_buf + pos -\nextra_offset\", yet the ext4_check_dir_entry() length argument uses the\nlarger extra_size. A position whose dirent header would extend past\nextra_size is therefore accepted, and the rescan loop\u0027s rec_len probe and\next4_check_dir_entry() dereference de-\u003erec_len before the entry is rejected.\n\nReject a position whose minimum-size dirent header would not fit within\nextra_size before forming de, in both the rescan and main loops, and pass\ninline_size rather than extra_size to ext4_check_dir_entry() so the length\ncheck matches the physical buffer."
    }
  ],
  "id": "CVE-2026-89786",
  "lastModified": "2026-09-16T15:18:08.860",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-16T09:17:09.330",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

GHSA-7XR2-RX94-5F89

Vulnerability from github – Published: 2026-09-16 09:30 – Updated: 2026-09-16 15:30

Details

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix out-of-bounds read in ext4_read_inline_dir()

ext4_read_inline_dir() can read a dirent header past the end of its inline buffer, triggering a slab-out-of-bounds read during getdents64():

BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry Read of size 2 at addr ffff88800f3dd23c by task exploit/148 ... __ext4_check_dir_entry ext4_read_inline_dir iterate_dir

The dirent payload lives in a buffer of exactly inline_size bytes:

dir_buf = kmalloc(inline_size, GFP_NOFS);

but iteration runs in a position space extra_offset bytes larger (extra_size = extra_offset + inline_size) so the synthetic "." and ".." land at their block-dir offsets. A dirent is formed at "dir_buf + pos - extra_offset", yet the ext4_check_dir_entry() length argument uses the larger extra_size. A position whose dirent header would extend past extra_size is therefore accepted, and the rescan loop's rec_len probe and ext4_check_dir_entry() dereference de->rec_len before the entry is rejected.

Reject a position whose minimum-size dirent header would not fit within extra_size before forming de, in both the rescan and main loops, and pass inline_size rather than extra_size to ext4_check_dir_entry() so the length check matches the physical buffer.

Severity

9.1 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-89786"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T09:17:09Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix out-of-bounds read in ext4_read_inline_dir()\n\next4_read_inline_dir() can read a dirent header past the end of its inline\nbuffer, triggering a slab-out-of-bounds read during getdents64():\n\n  BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry\n  Read of size 2 at addr ffff88800f3dd23c by task exploit/148\n   ...\n   __ext4_check_dir_entry\n   ext4_read_inline_dir\n   iterate_dir\n\nThe dirent payload lives in a buffer of exactly inline_size bytes:\n\n\tdir_buf = kmalloc(inline_size, GFP_NOFS);\n\nbut iteration runs in a position space extra_offset bytes larger\n(extra_size = extra_offset + inline_size) so the synthetic \".\" and \"..\"\nland at their block-dir offsets. A dirent is formed at \"dir_buf + pos -\nextra_offset\", yet the ext4_check_dir_entry() length argument uses the\nlarger extra_size. A position whose dirent header would extend past\nextra_size is therefore accepted, and the rescan loop\u0027s rec_len probe and\next4_check_dir_entry() dereference de-\u003erec_len before the entry is rejected.\n\nReject a position whose minimum-size dirent header would not fit within\nextra_size before forming de, in both the rescan and main loops, and pass\ninline_size rather than extra_size to ext4_check_dir_entry() so the length\ncheck matches the physical buffer.",
  "id": "GHSA-7xr2-rx94-5f89",
  "modified": "2026-09-16T15:30:57Z",
  "published": "2026-09-16T09:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89786"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1a1dea633b724a1c042dbcdb1fed27f410916688"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/36bf17bb90cdf7a623499b624b05acde4d2feef5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5fd20d4e50dd6e460b3ea8e4396f8553d4526f8f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6702c7da86d8cdb88d0fc57166286e115ffeb8c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9333cc809f0a89e001b814155a6cb8903a6274df"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b060861f662d4826dc700a1c3584243bb3474cfe"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d1e7c186555ad65554fd2f2b02f5a539aa35ae48"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-89786 (GCVE-0-2026-89786)

FKIE_CVE-2026-89786

GHSA-7XR2-RX94-5F89

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