{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90407",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-90407"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "wifi: ath11k: fix overreads in ath11k_wmi_process_csa_switch_count_event()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath11k: fix overreads in ath11k_wmi_process_csa_switch_count_event()\n\nThere is no policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, so\nthe parse infrastructure does not enforce a minimum length for the event\nstruct. Additionally, the num_vdevs field is taken directly from firmware\nand used as a loop bound over the vdev_ids array without checking that it\nfits within the TLV payload. Either condition can cause an out-of-bounds\nread.\n\nAdd a TLV policy entry for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT so\nthe parse infrastructure enforces a minimum length for the fixed-size event\nstruct. Add a helper ath11k_wmi_tlv_data_len() to recover the payload\nlength of a parsed TLV from the header preceding its data pointer. Use it\nin ath11k_wmi_process_csa_switch_count_event() to bound num_vdevs before\nthe loop.\n\nCompile tested only.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-90407"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f760b7d7e43584d2fa9bffcec1a04e502609f827"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d6625dc5f1fe42cd81b8c57a1f5317afb9b410ce"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0364926fb4bfb5b798e5fe2785b3023b4f767327"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5de2b8c53714ad58f2fda118cd29ebbe31b38665"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/208d7fdb85976a737a715b81d54efaff6703880c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-18T17:55:42Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.7,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The malformed bytes are firmware WMI_PDEV_CSA_SWITCH_COUNT_STATUS_EVENTID TLVs on CE2 (ath11k_ce_recv_process_cb \u2192 ath11k_htc_rx_completion_handler \u2192 ath11k_wmi_tlv_op_rx). num_vdevs and the event/ARRAY_UINT32 lengths are built by firmware, not taken from an 802.11 CSA IE, so this is a host-firmware HTC path, not WiFi frame injection.\nAC:L - wmi_tlv_policies had no min_len for WMI_TAG_PDEV_CSA_SWITCH_COUNT_STATUS_EVENT, and ath11k_wmi_process_csa_switch_count_event() used ev->num_vdevs as the vdev_ids[] bound with no compare to the ARRAY_UINT32 TLV length. Firmware setting current_switch_count=0 and an oversized num_vdevs makes the overread deterministic, with no race.\nPR:N - ath11k_wmi_tlv_op_rx() dispatches WMI_PDEV_CSA_SWITCH_COUNT_STATUS_EVENTID from the WMI HTC rx callback with no host uid, capability, or authentication check; the device firmware is the sole source of the event struct and vdev_ids array.\nUI:N - Firmware can send WMI_PDEV_CSA_SWITCH_COUNT_STATUS_EVENTID unsolicited on the WMI RX path; the overread of ev->current_switch_count/num_vdevs and vdev_ids[i] runs before the csa_active check and does not require the victim to start a channel switch, mount media, or open a file.\nS:U - The out-of-bounds loads of ev fields and vdev_ids[] stay inside the host kernel ath11k WMI parser and the CE RX skb heap; they do not cross a VM, IOMMU, or other separate security authority.\nC:H - ev->num_vdevs is a firmware u32 used as an unbounded index over vdev_ids[], so a count past the ARRAY_UINT32 TLV reads kernel heap beyond the WMI skb; unknown ids are also printed by ath11k_warn(\"Recvd csa status for unknown vdev %d\"). That is not a few-byte leak.\nI:N - The loop only reads vdev_ids[i] into ath11k_mac_get_arvif_by_vdev_id(); it never writes through the overread pointer. ieee80211_csa_finish() runs only if a looked-up vif already has csa_active, which is not an OOB write or hijack primitive from the overread.\nA:H - A firmware-chosen num_vdevs that walks vdev_ids[] past the CE RX skb can load from unmapped heap and oops/panic in ath11k_wmi_process_csa_switch_count_event(), which is a full kernel availability loss."
    }
  }
}