{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/lzo.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1641d058adfbd50cf95d54581ed5d142ee82c07f",
              "status": "affected",
              "version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278",
              "versionType": "git"
            },
            {
              "lessThan": "b0d27d43791b7a3057c3c4aedf9b4aa033d37c46",
              "status": "affected",
              "version": "a6e66e6f8c1b685e11b778bef614480a9c1a5278",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/btrfs/lzo.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace cbuf size, not against the compressed input size\n(compressed_len, the total folio bytes of the bio).  A crafted extent can\ncarry a segment whose seg_len passes the cbuf check but runs past the end\nof the bio, so copy_compressed_segment() walks off the last folio:\nget_current_folio() then returns the NULL folio from bio_next_folio(), and\nwith CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults.\n\n BUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383)\n Read of size 8 at addr 0000000000000000 by task kworker/u8:1/29\n Workqueue: btrfs-endio simple_end_io_work\n  kasan_report (mm/kasan/report.c:590)\n  lzo_decompress_bio (fs/btrfs/lzo.c:383)\n  end_bbio_compressed_read (fs/btrfs/compression.c:1065)\n  btrfs_bio_end_io (fs/btrfs/bio.c:135)\n  btrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285)\n  simple_end_io_work\n  process_one_work\n  worker_thread\n\nReject any segment whose payload would extend beyond compressed_len before\ncopying it, treating it as corruption like the other on-disk validation\nfailures in this function."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - On btrfs-backed NAS/cloud storage exported via nfsd or ksmbd, a remote client\u0027s read I/O is served by the server kernel through btrfs_do_readpage\u2192btrfs_submit_compressed_read\u2192lzo_decompress_bio, reaching the vulnerable LZO segment parser without local syscall access on the server.\nAC:L - A crafted on-disk LZO segment header with seg_len that passes the cbuf-size check but exceeds remaining compressed_len deterministically drives copy_compressed_segment past the last bio folio; no race, special memory layout, or rare kernel config is required.\nPR:N - Triggering needs only read access to btrfs content on an already-mounted/exported volume (e.g., NFS/ksmbd read); planting malformed LZO segment metadata is done via offline btrfs image crafting and does not require init-namespace root or a local account on the victim.\nUI:N - Exploitation is the attacker\u0027s own read against a btrfs volume that already contains the crafted LZO-compressed extent (backup restore, shared storage, or export); no separate victim mount, click, or plug-in action is needed beyond that read.\nS:U - Impact is a kernel NULL-pointer dereference and oops in the btrfs-endio workqueue on the host parsing attacker-supplied compressed data; this is standard host-kernel failure within one security authority, not VM escape or IOMMU bypass.\nC:N - The demonstrated failure is a null-ptr-deref read at address 0 in folio_size(NULL) when walking past the bio; unlike slab OOB reads in related btrfs LZO bugs, no adjacent kernel memory is disclosed before the fault.\nI:N - The bug faults during folio iteration before completing an out-of-bounds copy or decompression; there is no demonstrated or plausible kernel heap/stack write, control-flow hijack, or other integrity corruption beyond attacker-controlled on-disk bytes already in the bio.\nA:H - The NULL dereference in lzo_decompress_bio runs in btrfs-endio kworker context and produces a KASAN-reported kernel oops/panic; any process read (local or remote via NFS/ksmbd) of the crafted extent can repeatedly crash the host."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-29T06:21:31.506Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1641d058adfbd50cf95d54581ed5d142ee82c07f"
        },
        {
          "url": "https://git.kernel.org/stable/c/b0d27d43791b7a3057c3c4aedf9b4aa033d37c46"
        }
      ],
      "title": "btrfs: lzo: reject compressed segment that overflows the compressed input",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80631",
    "datePublished": "2026-08-28T06:48:47.166Z",
    "dateReserved": "2026-08-26T14:34:25.776Z",
    "dateUpdated": "2026-08-29T06:21:31.506Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}