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FKIE_CVE-2026-74392

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: dm: limit target bio polling to one shot dm_poll_bio() is the ->poll_bio() callback for a stacked dm device. The caller only knows about the dm queue, so it may decide to do a spinning poll if it thinks a single queue is being polled. Passing those flags unchanged to the mapped clone lets blk_mq_poll() spin on a target queue from inside dm_poll_bio(). With io_uring IOPOLL on a dm-stripe target this can keep a task in dm_poll_bio() -> bio_poll() -> blk_mq_poll() long enough to trigger an RCU CPU stall, before io_uring gets back to io_iopoll_check() and its need_resched() check. Keep dm's ->poll_bio() bounded by forcing one-shot polling for target bios. The caller can invoke dm_poll_bio() again if it wants to keep polling, and it also gets a chance to reap completions or reschedule between passes.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5aa0f9231cbacade065cedd8e9b5ebd067231171
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6c4ede3b771adbb3bf21ad4e8b8f2f6f6120c4f7
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6c4ede3b771adbb3bf21ad4e8b8f2f6f6120c4f7",
              "status": "affected",
              "version": "f22ecf9c14c12918e30f2179ef516e99eb8b2e49",
              "versionType": "git"
            },
            {
              "lessThan": "5aa0f9231cbacade065cedd8e9b5ebd067231171",
              "status": "affected",
              "version": "f22ecf9c14c12918e30f2179ef516e99eb8b2e49",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/md/dm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.19"
            },
            {
              "lessThan": "6.19",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndm: limit target bio polling to one shot\n\ndm_poll_bio() is the -\u003epoll_bio() callback for a stacked dm device.\nThe caller only knows about the dm queue, so it may decide to do a\nspinning poll if it thinks a single queue is being polled. Passing those\nflags unchanged to the mapped clone lets blk_mq_poll() spin on a target\nqueue from inside dm_poll_bio().\n\nWith io_uring IOPOLL on a dm-stripe target this can keep a task in\n\n  dm_poll_bio() -\u003e bio_poll() -\u003e blk_mq_poll()\n\nlong enough to trigger an RCU CPU stall, before io_uring gets back to\nio_iopoll_check() and its need_resched() check.\n\nKeep dm\u0027s -\u003epoll_bio() bounded by forcing one-shot polling for target\nbios. The caller can invoke dm_poll_bio() again if it wants to keep\npolling, and it also gets a chance to reap completions or reschedule\nbetween passes."
    }
  ],
  "id": "CVE-2026-74392",
  "lastModified": "2026-08-17T06:19:34.260",
  "metrics": {},
  "published": "2026-08-15T06:22:41.163",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5aa0f9231cbacade065cedd8e9b5ebd067231171"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6c4ede3b771adbb3bf21ad4e8b8f2f6f6120c4f7"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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