ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()

{
  "id": "081e6a4a2c1ab07d8648d04e165fc68ff8d9a824f9de9b9d12680ffbb4b917e0",
  "url": "https://osv.dev/vulnerability/CVE-2024-46735",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery() When two UBLK_CMD_START_USER_RECOVERY commands are submitted, the first one sets 'ubq->ubq_daemon' to NULL, and the second one triggers WARN in ublk_queue_reinit() and subsequently a NULL pointer dereference issue. Fix it by adding the check in ublk_ctrl_start_recovery() and return immediately in case of zero 'ub->nr_queues_ready'. BUG: kernel NULL pointer dereference, address: 0000000000000028 RIP: 0010:ublk_ctrl_start_recovery.constprop.0+0x82/0x180 Call Trace: ? __die+0x20/0x70 ? page_fault_oops+0x75/0x170 ? exc_page_fault+0x64/0x140 ? asm_exc_page_fault+0x22/0x30 ? ublk_ctrl_start_recovery.constprop.0+0x82/0x180 ublk_ctrl_uring_cmd+0x4f7/0x6c0 ? pick_next_task_idle+0x26/0x40 io_uring_cmd+0x9a/0x1b0 io_issue_sqe+0x193/0x3f0 io_wq_submit_work+0x9b/0x390 io_worker_handle_work+0x165/0x360 io_wq_worker+0xcb/0x2f0 ? finish_task_switch.isra.0+0x203/0x290 ? finish_task_switch.isra.0+0x203/0x290 ? __pfx_io_wq_worker+0x10/0x10 ret_from_fork+0x2d/0x50 ? __pfx_io_wq_worker+0x10/0x10 ret_from_fork_asm+0x1a/0x30",
    "evidence": "osv:CVE-2024-46735",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.51",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.10.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2024-46735",
      "aliases": [
        "CVE-2024-46735"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c732a852b419fa057b53657e2daaf9433940391c"
                },
                {
                  "fixed": "ca249435893dda766f3845c15ca77ca5672022d8"
                },
                {
                  "fixed": "136a29d8112df4ea0a57f9602ddf3579e04089dc"
                },
                {
                  "fixed": "7c890ef60bf417d3fe5c6f7a9f6cef0e1d77f74f"
                },
                {
                  "fixed": "e58f5142f88320a5b1449f96a146f2f24615c5c7"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-46735.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.1.0"
                },
                {
                  "fixed": "6.1.110"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.51"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.10.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-46735.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.390812037Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/136a29d8112df4ea0a57f9602ddf3579e04089dc",
        "https://git.kernel.org/stable/c/7c890ef60bf417d3fe5c6f7a9f6cef0e1d77f74f",
        "https://git.kernel.org/stable/c/ca249435893dda766f3845c15ca77ca5672022d8",
        "https://git.kernel.org/stable/c/e58f5142f88320a5b1449f96a146f2f24615c5c7",
        "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/46xxx/CVE-2024-46735.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-46735",
        "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/2024/46xxx/CVE-2024-46735.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-46735",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 514477,
  "published_at": "2024-09-18T07:11:57.279+00:00"
}