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FKIE_CVE-2026-72126

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Summary
In the Linux kernel, the following vulnerability has been resolved: can: isotp: use unconditional synchronize_rcu() in isotp_release() isotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister() and clears so->bound without waiting for a grace period. isotp_release() uses so->bound to decide whether it needs to call synchronize_rcu() before cancelling so->rxtimer, so when NETDEV_UNREGISTER runs first it skips that synchronize_rcu() and can cancel the timer while an in-flight isotp_rcv() is still executing and about to re-arm it via isotp_send_fc(), leading to a use-after-free timer callback on the freed socket. sakisho-bot remarked a problem with rtnl_lock held in isotp_notify(), therefore make isotp_release() always call synchronize_rcu() before cancelling the timers, regardless of so->bound. This still closes the original race (isotp_notify() clearing so->bound without waiting for in-flight isotp_rcv() callers before isotp_release() cancels the RX timer) without adding any RCU wait to the netdevice notifier path.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/can/isotp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "945d9894502cd9124f5d676181c542ed2000f7c0",
              "status": "affected",
              "version": "22bfa94db2ef6900c790884fa9461486516626e9",
              "versionType": "git"
            },
            {
              "lessThan": "59672aa4bcd8d32172c1ff6a179583981d6acabc",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "15413a082df69175c2f96aeab4c26fe1ff7cff03",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "6280eda96e0707264849fa7d036fed873c1f8a6d",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "cb6abc584a1bfab107ac003d64948a4aef1730aa",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "b88a511308779c225005d7994b8744561bdbafbc",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "b8278ff605187ef3fa0f2705e93251cce4c4f8ee",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "lessThan": "9b1a02e0d980ac6b0e36a90378f847062f81d7e4",
              "status": "affected",
              "version": "14a4696bc3118ba49da28f79280e1d55603aa737",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "80c6ddf771df2ef786f28c1ca5919b3f1080091b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ebf91625b3e404bd2b4b694c7ee71c1e8f8bd08f",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.261",
              "status": "affected",
              "version": "5.10.50",
              "versionType": "semver"
            },
            {
              "lessThan": "5.13",
              "status": "affected",
              "version": "5.12.17",
              "versionType": "semver"
            },
            {
              "lessThan": "5.14",
              "status": "affected",
              "version": "5.13.2",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/can/isotp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "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\ncan: isotp: use unconditional synchronize_rcu() in isotp_release()\n\nisotp_notify() unregisters the (RCU) CAN filters via can_rx_unregister()\nand clears so-\u003ebound without waiting for a grace period. isotp_release()\nuses so-\u003ebound to decide whether it needs to call synchronize_rcu()\nbefore cancelling so-\u003erxtimer, so when NETDEV_UNREGISTER runs first it\nskips that synchronize_rcu() and can cancel the timer while an\nin-flight isotp_rcv() is still executing and about to re-arm it via\nisotp_send_fc(), leading to a use-after-free timer callback on the\nfreed socket.\n\nsakisho-bot remarked a problem with rtnl_lock held in isotp_notify(),\ntherefore make isotp_release() always call synchronize_rcu() before\ncancelling the timers, regardless of so-\u003ebound. This still closes the\noriginal race (isotp_notify() clearing so-\u003ebound without waiting for\nin-flight isotp_rcv() callers before isotp_release() cancels the RX\ntimer) without adding any RCU wait to the netdevice notifier path."
    }
  ],
  "id": "CVE-2026-72126",
  "lastModified": "2026-08-17T06:18:12.213",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:21:29.963",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/15413a082df69175c2f96aeab4c26fe1ff7cff03"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/59672aa4bcd8d32172c1ff6a179583981d6acabc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6280eda96e0707264849fa7d036fed873c1f8a6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/945d9894502cd9124f5d676181c542ed2000f7c0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9b1a02e0d980ac6b0e36a90378f847062f81d7e4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b8278ff605187ef3fa0f2705e93251cce4c4f8ee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b88a511308779c225005d7994b8744561bdbafbc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cb6abc584a1bfab107ac003d64948a4aef1730aa"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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