netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call

{
  "id": "f0b4f49235ccf5c49458a1c7b39a74bcd48f1b096a5d0f5cd653ae21061a2b95",
  "url": "https://osv.dev/vulnerability/CVE-2026-64065",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call The multiple runs of generic/013 test-case is capable to reproduce a kernel BUG at mm/filemap.c:1504 with probability of 30%. while true; do sudo ./check generic/013 done [ 9849.452376] page: refcount:3 mapcount:0 mapping:00000000e58ff252 index:0x10781 pfn:0x1c322 [ 9849.452412] memcg:ffff8881a1915800 [ 9849.452417] aops:ceph_aops ino:1000058db9e dentry name(?):\"f9XXXXXX\" [ 9849.452432] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) [ 9849.452441] raw: 0017ffffc0000000 0000000000000000 dead000000000122 ffff88816110d248 [ 9849.452445] raw: 0000000000010781 0000000000000000 00000003ffffffff ffff8881a1915800 [ 9849.452447] page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) [ 9849.452474] ------------[ cut here ]------------ [ 9849.452476] kernel BUG at mm/filemap.c:1504! [ 9849.478635] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 9849.481772] CPU: 2 UID: 0 PID: 84223 Comm: fsstress Not tainted 7.0.0-rc1+ #18 PREEMPT(full) [ 9849.482881] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-9.fc43 06/1 0/2025 [ 9849.484539] RIP: 0010:folio_unlock+0x85/0xa0 [ 9849.485076] Code: 89 df 31 f6 e8 1c f3 ff ff 48 8b 5d f8 c9 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 48 c7 c6 80 6c d9 a7 48 89 df e8 4b b3 10 00 <0f> 0b 48 89 df e8 21 e6 2c 00 eb 9d 0f 1f 40 00 66 66 2e 0f 1f 84 [ 9849.493818] RSP: 0018:ffff8881bb8076b0 ",
    "evidence": "osv:CVE-2026-64065",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.92",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.34",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-64065",
      "aliases": [
        "CVE-2026-64065"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ee4cdf7ba857a894ad1650d6ab77669cbbfa329e"
                },
                {
                  "fixed": "51ffb788f074c0a61953086f49008028c1e7b645"
                },
                {
                  "fixed": "b63971238beb79cf701dac33c6cefc56c07c89fa"
                },
                {
                  "fixed": "5ad05b6f5df296ef046589f222bb2587495b991e"
                },
                {
                  "fixed": "dc7832d05deb4d632e8035e3299e31a3528fa0d0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64065.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.12.0"
                },
                {
                  "fixed": "6.12.92"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.34"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64065.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:28.027305788Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/51ffb788f074c0a61953086f49008028c1e7b645",
        "https://git.kernel.org/stable/c/5ad05b6f5df296ef046589f222bb2587495b991e",
        "https://git.kernel.org/stable/c/b63971238beb79cf701dac33c6cefc56c07c89fa",
        "https://git.kernel.org/stable/c/dc7832d05deb4d632e8035e3299e31a3528fa0d0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64065.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64065",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64065.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64065",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 494581,
  "published_at": "2026-07-19T15:39:43.397+00:00"
}