FKIE_CVE-2026-68160

Vulnerability from fkie_nvd - Published: 2026-08-10 13:20 - Updated: 2026-08-19 17:20
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps() ceph_handle_caps() reads snap_trace_len from the wire-format ceph_mds_caps header and uses it unconditionally to build a fake end pointer (snaptrace + snaptrace_len) that is later handed to ceph_update_snap_trace() in the CEPH_CAP_OP_IMPORT case: snaptrace = h + 1; snaptrace_len = le32_to_cpu(h->snap_trace_len); p = snaptrace + snaptrace_len; ... case CEPH_CAP_OP_IMPORT: if (snaptrace_len) { ... if (ceph_update_snap_trace(mdsc, snaptrace, snaptrace + snaptrace_len, false, &realm)) { ... } ceph_update_snap_trace() then decodes a struct ceph_mds_snap_realm from snaptrace using ceph_decode_need(&p, e, sizeof(*ri), bad) with the attacker-supplied fake end e == snaptrace + snaptrace_len. With snaptrace_len == 0xFFFFFFFF the bound check is trivially satisfied, ri = p reads sizeof(struct ceph_mds_snap_realm) past the legitimate msg->front buffer, and ri->num_snaps / ri->num_prior_parent_snaps then drive further out-of-bounds reads of the encoded snap arrays. The eleven msg_version >= 2 .. msg_version >= 12 decoder blocks above the op switch each catch this OOB through their ceph_decode_*_safe() / ceph_decode_need() helpers, but they sit behind a hdr.version-gated if, so a malicious or compromised MDS that sets msg->hdr.version = 1 reaches the IMPORT path with no version-gated decoder having validated snap_trace_len. The shape has been present since ceph_handle_caps() was introduced. Validate snap_trace_len against the message front buffer before consuming it, using the canonical ceph_decode_need() / ceph_has_room() helper. The helper bounds the length with subtraction (n <= end - p, guarded by end >= p) rather than pointer addition, so it is wrap-safe for the attacker-controlled u32 length on 32-bit builds where p + snap_trace_len could overflow the address space. This matches the rest of the ceph decode path (e.g. the pool_ns_len check a few lines below), and the existing goto bad cleanup already covers this exit path.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/03b417afce19ee6b6e61f1bbbbebac924c9f36d1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0c011137194036424e974677e0f1592e22a33d8c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4dbc71bcaf9a30abf3920a4e2cc4ed33bba78c02
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/71893c342a26bcff92eaab0b2b75d64aed19308a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9081c71796724ffe96cba253f68fbe42363c5295
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a4228b93706fb74a484e6ffb271c1cc2af3a2ddb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc93f68a31c9b831abf2db8647b5f5b10329d793
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f913192fc782288e060dafc329b2346934be34cc
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/caps.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f913192fc782288e060dafc329b2346934be34cc",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "0c011137194036424e974677e0f1592e22a33d8c",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "cc93f68a31c9b831abf2db8647b5f5b10329d793",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "9081c71796724ffe96cba253f68fbe42363c5295",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "03b417afce19ee6b6e61f1bbbbebac924c9f36d1",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "a4228b93706fb74a484e6ffb271c1cc2af3a2ddb",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "71893c342a26bcff92eaab0b2b75d64aed19308a",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            },
            {
              "lessThan": "4dbc71bcaf9a30abf3920a4e2cc4ed33bba78c02",
              "status": "affected",
              "version": "a8599bd821d084d04a3290fffae1071624ec00ea",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/ceph/caps.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.34"
            },
            {
              "lessThan": "2.6.34",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps()\n\nceph_handle_caps() reads snap_trace_len from the wire-format\nceph_mds_caps header and uses it unconditionally to build a fake\nend pointer (snaptrace + snaptrace_len) that is later handed to\nceph_update_snap_trace() in the CEPH_CAP_OP_IMPORT case:\n\n    snaptrace     = h + 1;\n    snaptrace_len = le32_to_cpu(h-\u003esnap_trace_len);\n    p             = snaptrace + snaptrace_len;\n    ...\n    case CEPH_CAP_OP_IMPORT:\n        if (snaptrace_len) {\n            ...\n            if (ceph_update_snap_trace(mdsc, snaptrace,\n                                       snaptrace + snaptrace_len,\n                                       false, \u0026realm)) { ... }\n\nceph_update_snap_trace() then decodes a struct ceph_mds_snap_realm\nfrom snaptrace using ceph_decode_need(\u0026p, e, sizeof(*ri), bad)\nwith the attacker-supplied fake end e == snaptrace + snaptrace_len.\nWith snaptrace_len == 0xFFFFFFFF the bound check is trivially\nsatisfied, ri = p reads sizeof(struct ceph_mds_snap_realm) past\nthe legitimate msg-\u003efront buffer, and ri-\u003enum_snaps /\nri-\u003enum_prior_parent_snaps then drive further out-of-bounds\nreads of the encoded snap arrays.\n\nThe eleven msg_version \u003e= 2 .. msg_version \u003e= 12 decoder blocks\nabove the op switch each catch this OOB through their\nceph_decode_*_safe() / ceph_decode_need() helpers, but they sit\nbehind a hdr.version-gated if, so a malicious or compromised\nMDS that sets msg-\u003ehdr.version = 1 reaches the IMPORT path with\nno version-gated decoder having validated snap_trace_len. The\nshape has been present since ceph_handle_caps() was introduced.\n\nValidate snap_trace_len against the message front buffer before\nconsuming it, using the canonical ceph_decode_need() / ceph_has_room()\nhelper.  The helper bounds the length with subtraction (n \u003c= end - p,\nguarded by end \u003e= p) rather than pointer addition, so it is wrap-safe\nfor the attacker-controlled u32 length on 32-bit builds where\np + snap_trace_len could overflow the address space.  This matches the\nrest of the ceph decode path (e.g. the pool_ns_len check a few lines\nbelow), and the existing goto bad cleanup already covers this exit\npath."
    }
  ],
  "id": "CVE-2026-68160",
  "lastModified": "2026-08-19T17:20:33.317",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-10T13:20:02.300",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/03b417afce19ee6b6e61f1bbbbebac924c9f36d1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0c011137194036424e974677e0f1592e22a33d8c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4dbc71bcaf9a30abf3920a4e2cc4ed33bba78c02"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/71893c342a26bcff92eaab0b2b75d64aed19308a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9081c71796724ffe96cba253f68fbe42363c5295"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a4228b93706fb74a484e6ffb271c1cc2af3a2ddb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc93f68a31c9b831abf2db8647b5f5b10329d793"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f913192fc782288e060dafc329b2346934be34cc"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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