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CVE-2026-98965

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ice: Restore Ordered MMIO Writes for Tx Doorbells The DQL accounting state which tracks the number of bytes queued for the NIC to transmit, namely dql->num_queued, is updated by the ICE driver when it invokes __netdev_tx_sent_queue(). Subsequently the driver updates the hardware queue tail allowing the NIC to begin processing the work queue. The queue accounting update should be ordered before the NIC begins transmitting descriptors. The transmit path currently updates the hardware doorbell using writel_relaxed(), which (on arm64) does not provide the same ordering guarantees between writes to normal memory and writes to MMIO registers that writel() does. This introduces a potential race where the NIC begins transmitting descriptors before the dql->num_queued update is globally visible. If the NIC finishes before the update is observed by dql_completed(), it detects an invalid state where more bytes have been completed than have been queued. When this happens the following BUG_ON is triggered. BUG_ON(count > num_queued - dql->num_completed); This has been observed and manifests as the following crash (note that the trace has been trimmed) in an environment with sustained network load that uses an Intel Corporation Ethernet Controller E810-XXV for SFP (rev 02) on an arm64 machine. Replacing writel_relaxed() with writel() in a test kernel eliminated the crash in the user's workload, which previously reproduced the issue reliably. kernel BUG at lib/dynamic_queue_limits.c:99 Internal error: Oops - BUG: 00000000f2000800 [#1] SMP pc : dql_completed+0x268/0x2a0 lr : ice_clean_tx_irq+0x1d4/0x620 [ice] Call trace: dql_completed+0x268/0x2a0 (P) ice_napi_poll+0x94/0x520 [ice] __napi_poll+0x48/0x3f0 net_rx_action+0x194/0x420 This restores the behaviour prior to commit ccde82e90946 ("ice: add E830 Earliest TxTime First Offload support"), which changed the notification mechanism from writel() to writel_relaxed().

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-23 13:17:17.950000
Last modified
2026-10-24 14:16:49.640000
View original CVE JSON
{
  "id": "CVE-2026-98965",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:17.950",
  "lastModified": "2026-10-24T14:16:49.640",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nice: Restore Ordered MMIO Writes for Tx Doorbells\n\nThe DQL accounting state which tracks the number of bytes queued for the\nNIC to transmit, namely dql->num_queued, is updated by the ICE driver\nwhen it invokes __netdev_tx_sent_queue(). Subsequently the driver\nupdates the hardware queue tail allowing the NIC to begin processing the\nwork queue. The queue accounting update should be ordered before the NIC\nbegins transmitting descriptors.\n\nThe transmit path currently updates the hardware doorbell using\nwritel_relaxed(), which (on arm64) does not provide the same ordering\nguarantees between writes to normal memory and writes to MMIO registers\nthat writel() does. This introduces a potential race where the NIC\nbegins transmitting descriptors before the dql->num_queued update is\nglobally visible. If the NIC finishes before the update is observed by\ndql_completed(), it detects an invalid state where more bytes have been\ncompleted than have been queued. When this happens the following BUG_ON\nis triggered.\n\n  BUG_ON(count > num_queued - dql->num_completed);\n\nThis has been observed and manifests as the following crash (note that\nthe trace has been trimmed) in an environment with sustained network\nload that uses an Intel Corporation Ethernet Controller E810-XXV for SFP\n(rev 02) on an arm64 machine. Replacing writel_relaxed() with writel()\nin a test kernel eliminated the crash in the user's workload, which\npreviously reproduced the issue reliably.\n\n  kernel BUG at lib/dynamic_queue_limits.c:99\n\nInternal error: Oops - BUG: 00000000f2000800 [#1] SMP\npc : dql_completed+0x268/0x2a0\nlr : ice_clean_tx_irq+0x1d4/0x620 [ice]\nCall trace:\ndql_completed+0x268/0x2a0 (P)\nice_napi_poll+0x94/0x520 [ice]\n__napi_poll+0x48/0x3f0\nnet_rx_action+0x194/0x420\n\nThis restores the behaviour prior to commit ccde82e90946 (\"ice: add E830\nEarliest TxTime First Offload support\"), which changed the notification\nmechanism from writel() to writel_relaxed()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/ethernet/intel/ice/ice_txrx.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "ccde82e909467abdf098a8ee6f63e1ecf9a47ce5",
              "lessThan": "b7725acf9c574debb97ae1613569ac9e148438be",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ccde82e909467abdf098a8ee6f63e1ecf9a47ce5",
              "lessThan": "f94ab1fffd009250d72c6dc1662cb84467ac5365",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ccde82e909467abdf098a8ee6f63e1ecf9a47ce5",
              "lessThan": "7a579dec8423bba7bec96fcfcb2e30838b0858ee",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/ethernet/intel/ice/ice_txrx.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.18",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.18",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/7a579dec8423bba7bec96fcfcb2e30838b0858ee",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b7725acf9c574debb97ae1613569ac9e148438be",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f94ab1fffd009250d72c6dc1662cb84467ac5365",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}