FKIE_CVE-2026-74472

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-19 17:21
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev() ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into ub->dev_info and then fixes up the fields the driver owns, but misses ->state and ->ublksrv_pid. A device added with ->state = UBLK_S_DEV_LIVE passes the "->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV right after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A poisoned ->state also gets START_USER_RECOVERY and the char device read/write path onto a device that was never started, and wedges START_DEV at -EEXIST. A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an unrelated task as the ublk server. Reset both after the memcpy(), as ublk_detach_disk() does. Userspace only ever reads these back, so correcting them silently breaks nothing. ADD_DEV has copied ->state in unsanitized since ublk was merged, but back then it was harmless: the gendisk was allocated during ADD_DEV, and both teardown and the START_DEV -EEXIST check keyed off disk_live() rather than ->state. The oops became reachable once the disk allocation moved to START_DEV and those checks switched to ->state.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/127033b79383a3e78361d7e971588aa8849f5124
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/205feb72e5beb3140e4e1403b6cff30cf739bab9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/787c944502e7e63d20a9201bada77e0dd924f458
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b67ce16b26ad0f14cfd6071013840aa95f823bea
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e65848e4ce352bac9e3465099354c8b8f845391f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ee41b00858ca65b4428e99efe39a4277c1f043d2
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "787c944502e7e63d20a9201bada77e0dd924f458",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            },
            {
              "lessThan": "ee41b00858ca65b4428e99efe39a4277c1f043d2",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            },
            {
              "lessThan": "b67ce16b26ad0f14cfd6071013840aa95f823bea",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            },
            {
              "lessThan": "205feb72e5beb3140e4e1403b6cff30cf739bab9",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            },
            {
              "lessThan": "127033b79383a3e78361d7e971588aa8849f5124",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            },
            {
              "lessThan": "e65848e4ce352bac9e3465099354c8b8f845391f",
              "status": "affected",
              "version": "6d9e6dfdf3b207701471f364121c67eefb000682",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/ublk_drv.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.0"
            },
            {
              "lessThan": "6.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.151",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "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\nublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()\n\nublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into\nub-\u003edev_info and then fixes up the fields the driver owns, but misses\n-\u003estate and -\u003eublksrv_pid.\n\nA device added with -\u003estate = UBLK_S_DEV_LIVE passes the\n\"-\u003estate != UBLK_S_DEV_DEAD\" test that ublk_stop_dev_unlocked() uses as its\nproxy for \"a disk is attached\", while -\u003eub_disk is still NULL, so DEL_DEV\nright after ADD_DEV oopses in del_gendisk().  UBLK_S_DEV_QUIESCED plus\nUBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev().  A\npoisoned -\u003estate also gets START_USER_RECOVERY and the char device\nread/write path onto a device that was never started, and wedges START_DEV\nat -EEXIST.  A poisoned -\u003eublksrv_pid just makes GET_DEV_INFO report an\nunrelated task as the ublk server.\n\nReset both after the memcpy(), as ublk_detach_disk() does.  Userspace only\never reads these back, so correcting them silently breaks nothing.\n\nADD_DEV has copied -\u003estate in unsanitized since ublk was merged, but back\nthen it was harmless: the gendisk was allocated during ADD_DEV, and both\nteardown and the START_DEV -EEXIST check keyed off disk_live() rather than\n-\u003estate.  The oops became reachable once the disk allocation moved to\nSTART_DEV and those checks switched to -\u003estate."
    }
  ],
  "id": "CVE-2026-74472",
  "lastModified": "2026-08-19T17:21:04.490",
  "metrics": {},
  "published": "2026-08-15T13:17:51.953",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/127033b79383a3e78361d7e971588aa8849f5124"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/205feb72e5beb3140e4e1403b6cff30cf739bab9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/787c944502e7e63d20a9201bada77e0dd924f458"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b67ce16b26ad0f14cfd6071013840aa95f823bea"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e65848e4ce352bac9e3465099354c8b8f845391f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ee41b00858ca65b4428e99efe39a4277c1f043d2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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