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libceph: fix two unsafe bare decodes in decode_lockers()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: libceph: fix two unsafe bare decodes in decode_lockers() decode_lockers() in cls_lock_client.c contains two bare decode operations that allow a malicious or compromised OSD to trigger slab-out-of-bounds reads: 1. ceph_decode_32(p) at the num_lockers field has no preceding bounds check. ceph_start_decoding() accepts struct_len=0 as valid -- the internal ceph_decode_need(p, end, 0, bad) always passes -- so when an OSD sends struct_len=0, ceph_start_decoding() returns success with p == end. The immediately following bare ceph_decode_32(p) then reads 4 bytes past the validated buffer boundary. The garbage value is passed directly to kzalloc_objs() as the locker count. The sibling function decode_watchers() in osd_client.c already uses ceph_decode_32_safe() after its own ceph_start_decoding() call. decode_lockers() was the only site using the bare variant. 2. ceph_decode_8(p) after the decode_locker() loop has no preceding bounds check. If an OSD crafts num_lockers such that the loop advances p exactly to end, the subsequent bare ceph_decode_8(p) reads one byte past the validated buffer boundary. The result is passed directly into *type, which is used as a lock type discriminator by callers, giving an OSD-controlled one-byte OOB read with direct influence over the lock type field. Fix both by replacing bare operations with their safe variants: ceph_decode_32(p) -> ceph_decode_32_safe(p, end, *num_lockers, err_inva

Announced Source revision 1
Original source ↗

CVE-2026-68082

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-68082

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "c8ade01170a27d8ede0d761c255268af81e417f8",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "001835c599899ef1bd3506a815110a6374451554",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "7c422364acd93d7da1dfc27d6b54635a269653a1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "02430f6f729b297e803d0605871f0a670b4eafd6",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "57ba829804fe6d34bbac3b826c4b15c1caa54862",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "89df5d71f83f8e2781286798fd8ae5e42cf5f1a7",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "a54be593d0b749161b08a1e56189b2cb9114267a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d4ed4a530562881cc5225050e42d96034f405aae",
        "lessThan": "a109a556115271ca7896dcda7b4b7e45e156c227",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/ceph/cls_lock_client.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.9"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.9",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.266",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.217",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.184",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.153",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.105",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.46",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.6",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/ceph/cls_lock_client.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-68082

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#41106 · Revision 1
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Publisher date
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