CVE-2026-98543 (GCVE-0-2026-98543)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:18 – Updated: 2026-10-19 09:21
VLAI
Title
bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: fs/xattr: don't assume the inode is locked in path_unlink/path_rmdir bpf_lsm_has_d_inode_locked() makes the verifier rewrite bpf_[set|remove]_dentry_xattr() to the _locked variants, which assume that the caller already holds the inode's i_rwsem. The path_unlink and path_rmdir hooks are listed, but security_path_unlink() and security_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the victim inode's i_rwsem, so a sleepable BPF LSM program attached to either hook mutates the victim's xattrs without the lock held. Drop the two path hooks from d_inode_locked_hooks so that the verifier keeps the locking bpf_[set|remove]_dentry_xattr() variants, which take the lock themselves.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6843 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 56467292794b800164df20c076c409ac548e56ec , < 7504b677c4370c9e4b153c553ff8831c093b1ff6 (git)
Affected: 56467292794b800164df20c076c409ac548e56ec , < 640d37fbd34d03af727dbc567f48c0203d1de6b4 (git)
Affected: 56467292794b800164df20c076c409ac548e56ec , < 35d442ed1f86465e49df3119fb898f985186db13 (git)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.55 , ≤ 6.18.* (semver)
Unaffected: 7.2.9 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
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        {
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          "product": "Linux",
          "programFiles": [
            "fs/bpf_fs_kfuncs.c"
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              "operator": "OR"
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: fs/xattr: don\u0027t assume the inode is locked in path_unlink/path_rmdir\n\nbpf_lsm_has_d_inode_locked() makes the verifier rewrite\nbpf_[set|remove]_dentry_xattr() to the _locked variants, which assume\nthat the caller already holds the inode\u0027s i_rwsem.  The path_unlink and\npath_rmdir hooks are listed, but security_path_unlink() and\nsecurity_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the\nvictim inode\u0027s i_rwsem, so a sleepable BPF LSM program attached to\neither hook mutates the victim\u0027s xattrs without the lock held.\n\nDrop the two path hooks from d_inode_locked_hooks so that the verifier\nkeeps the locking bpf_[set|remove]_dentry_xattr() variants, which take\nthe lock themselves."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:21:26.563Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
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          "url": "https://git.kernel.org/stable/c/35d442ed1f86465e49df3119fb898f985186db13"
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      "title": "bpf: fs/xattr: don\u0027t assume the inode is locked in path_unlink/path_rmdir",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98543",
    "datePublished": "2026-10-18T15:18:10.823Z",
    "dateReserved": "2026-09-25T10:25:14.356Z",
    "dateUpdated": "2026-10-19T09:21:26.563Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "initial_release_date": "2026-10-20T22:23:36.000Z",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "bpf: fs/xattr: don\u0027t assume the inode is locked in path_unlink/path_rmdir",
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      "version": "2"
    },
    "nvd": {
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                "product": "Linux",
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        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: fs/xattr: don\u0027t assume the inode is locked in path_unlink/path_rmdir\n\nbpf_lsm_has_d_inode_locked() makes the verifier rewrite\nbpf_[set|remove]_dentry_xattr() to the _locked variants, which assume\nthat the caller already holds the inode\u0027s i_rwsem.  The path_unlink and\npath_rmdir hooks are listed, but security_path_unlink() and\nsecurity_path_rmdir() run before vfs_unlink()/vfs_rmdir() take the\nvictim inode\u0027s i_rwsem, so a sleepable BPF LSM program attached to\neither hook mutates the victim\u0027s xattrs without the lock held.\n\nDrop the two path hooks from d_inode_locked_hooks so that the verifier\nkeeps the locking bpf_[set|remove]_dentry_xattr() variants, which take\nthe lock themselves."
          }
        ],
        "id": "CVE-2026-98543",
        "lastModified": "2026-10-19T10:19:10.220",
        "metrics": {},
        "published": "2026-10-18T16:17:06.200",
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      "title": "kernel: bpf: fs/xattr: don\u0027t assume the inode is locked in path_unlink/path_rmdir",
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    }
  }
}



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