dm: fix unconditional IO throttle caused by REQ_PREFLUSH

{
  "id": "aa00ea9e0fb48e278fb02149b50f817120e51c7e1367e5ed5fd79e62fdc2ffb9",
  "url": "https://osv.dev/vulnerability/CVE-2025-38063",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "dm: fix unconditional IO throttle caused by REQ_PREFLUSH",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: dm: fix unconditional IO throttle caused by REQ_PREFLUSH When a bio with REQ_PREFLUSH is submitted to dm, __send_empty_flush() generates a flush_bio with REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC, which causes the flush_bio to be throttled by wbt_wait(). An example from v5.4, similar problem also exists in upstream: crash> bt 2091206 PID: 2091206 TASK: ffff2050df92a300 CPU: 109 COMMAND: \"kworker/u260:0\" #0 [ffff800084a2f7f0] __switch_to at ffff80004008aeb8 #1 [ffff800084a2f820] __schedule at ffff800040bfa0c4 #2 [ffff800084a2f880] schedule at ffff800040bfa4b4 #3 [ffff800084a2f8a0] io_schedule at ffff800040bfa9c4 #4 [ffff800084a2f8c0] rq_qos_wait at ffff8000405925bc #5 [ffff800084a2f940] wbt_wait at ffff8000405bb3a0 #6 [ffff800084a2f9a0] __rq_qos_throttle at ffff800040592254 #7 [ffff800084a2f9c0] blk_mq_make_request at ffff80004057cf38 #8 [ffff800084a2fa60] generic_make_request at ffff800040570138 #9 [ffff800084a2fae0] submit_bio at ffff8000405703b4 #10 [ffff800084a2fb50] xlog_write_iclog at ffff800001280834 [xfs] #11 [ffff800084a2fbb0] xlog_sync at ffff800001280c3c [xfs] #12 [ffff800084a2fbf0] xlog_state_release_iclog at ffff800001280df4 [xfs] #13 [ffff800084a2fc10] xlog_write at ffff80000128203c [xfs] #14 [ffff800084a2fcd0] xlog_cil_push at ffff8000012846dc [xfs] #15 [ffff800084a2fda0] xlog_cil_push_work at ffff800001284a2c [xfs] #16 [ffff800084a2fdb0] process_one_work at ffff800040111d08 #17 [ffff800084a2fe00] ",
    "evidence": "osv:CVE-2025-38063",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.141",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.93",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.31",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.14.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-38063",
      "aliases": [
        "CVE-2025-38063"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e34cbd307477ae07c5d8a8d0bd15e65a9ddaba5c"
                },
                {
                  "fixed": "95d08924335f3b6f4ea0b92ebfe4fe0731c502d9"
                },
                {
                  "fixed": "52aa28f7b1708d76e315d78b5ed397932a1a97c3"
                },
                {
                  "fixed": "b55a97d1bd4083729a60d19beffe85d4c96680de"
                },
                {
                  "fixed": "2858cda9a8d95e6deee7e3b0a26adde696a9a4f5"
                },
                {
                  "fixed": "88f7f56d16f568f19e1a695af34a7f4a6ce537a6"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38063.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.10.0"
                },
                {
                  "fixed": "6.1.141"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.93"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.31"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.14.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38063.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.419125071Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-082556.html",
        "https://git.kernel.org/stable/c/2858cda9a8d95e6deee7e3b0a26adde696a9a4f5",
        "https://git.kernel.org/stable/c/52aa28f7b1708d76e315d78b5ed397932a1a97c3",
        "https://git.kernel.org/stable/c/88f7f56d16f568f19e1a695af34a7f4a6ce537a6",
        "https://git.kernel.org/stable/c/95d08924335f3b6f4ea0b92ebfe4fe0731c502d9",
        "https://git.kernel.org/stable/c/b55a97d1bd4083729a60d19beffe85d4c96680de",
        "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38063.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-38063",
        "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/2025/38xxx/CVE-2025-38063.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-38063",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 500290,
  "published_at": "2025-06-18T09:33:41.977+00:00"
}