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CVE-2026-63874

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net: mctp: usb: fix race between urb completion and rx_retry cancellation It's possible that sequencing between setting ->stopped and cancelling the rx_retry work (in ndo_stop) could leave us with an urb queued: T1: ndo_stop T2: rx_retry_work ------------ ---------------- LD: ->stopped => false ST: ->stopped <= true usb_kill_urb() mctp_usb_rx_queue() usb_submit_urb() cancel_delayed_work_sync() That urb completion can then re-schedule rx_retry_work. Strenghen the sequencing between the stop (preventing another requeue) and the cancel by updating both atomically under a new rx lock. After setting ->rx_stopped, and cancelling pending work, we know that the requeue cannot occur, so all that's left is killing any pending urb.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 15:16:54.450000
Last modified
2026-10-30 14:55:31.457000
View original CVE JSON 
{
  "id": "CVE-2026-63874",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-19T15:16:54.450",
  "lastModified": "2026-10-30T14:55:31.457",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mctp: usb: fix race between urb completion and rx_retry cancellation\n\nIt's possible that sequencing between setting ->stopped and cancelling\nthe rx_retry work (in ndo_stop) could leave us with an urb queued:\n\n    T1: ndo_stop                  T2: rx_retry_work\n    ------------                  ----------------\n                                  LD: ->stopped => false\n    ST: ->stopped <= true\n    usb_kill_urb()\n                                  mctp_usb_rx_queue()\n                                    usb_submit_urb()\n    cancel_delayed_work_sync()\n\nThat urb completion can then re-schedule rx_retry_work.\n\nStrenghen the sequencing between the stop (preventing another requeue)\nand the cancel by updating both atomically under a new rx lock. After\nsetting ->rx_stopped, and cancelling pending work, we know that the\nrequeue cannot occur, so all that's left is killing any pending urb."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/mctp/mctp-usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "status": "unaffected"
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              "versionType": "original_commit_for_fix",
              "status": "unaffected"
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  ],
  "metrics": {
    "cvssMetricV31": [
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        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ]
    }
  ],
  "configurations": [
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}