{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90353",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-90353"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "wifi: mt76: mt7915: fix ext PHY use-after-free on register error path",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7915: fix ext PHY use-after-free on register error path\n\nAfter mt7915_register_ext_phy() succeeded, a failure of the main PHY\nmt7915_init_debugfs() or mt7915_coredump_register() unwound through\nfree_phy2, which called ieee80211_free_hw() on the ext PHY hw while it\nwas still registered with mac80211, since mt76_unregister_device() only\nunregisters the main hw. Unregister the ext PHY (thermal + phy + hw)\nfirst and skip the redundant free.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-90353"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/aa55bec92ba7747dd08feff409f8074c5e052e71"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ad706fcf6255494613b94418e7243d98065dbeaf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/34058ad122f7524e33df8e38caba4b1d803b025a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a7fd3bae8e11a7c00df6a5021d9ef248ae9f9bf5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/648f5f03ff50d4bd719106ace0cdf1d8be02cbdd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/15b960014f24dce5388d4a2e7274e6490cb3c421"
    }
  ],
  "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": 7.0,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The UAF is in mt7915_register_device()'s free_phy2 unwind, reached only from mt7915_pci_probe() and mt798x_wmac_probe() when mt7915_init_debugfs() or mt7915_coredump_register() fails after mt7915_register_ext_phy(); no 802.11 frame or nl80211 command supplies the triggering data.\nAC:H - mt7915_init_debugfs() always returns 0, so the live branch is mt7915_coredump_register() failing its vzalloc of struct mt7915_crash_data after mt7915_alloc_ext_phy() produced phy2 (DBDC). That one-shot ENOMEM during pci/platform probe is not something an attacker can reliably force.\nPR:L - After ieee80211_free_hw() on the still-registered ext PHY, mt76_unregister_device() drops only the main hw, leaving the ext wiphy, the default STA vif from ieee80211_register_hw(), and mt7915_thermal_ops (cdev->devdata = phy) reachable via nl80211 and thermal sysfs without init-namespace root or PCI bind capability.\nUI:N - No victim must mount media or open a file; once the probe unwind runs, udev, mac80211's leftover workqueue/inetaddr notifier, or the attacker\u2019s own nl80211/thermal access touches the still-registered ext PHY.\nS:U - ieee80211_free_hw() frees the ext PHY's ieee80211_local/wiphy/sband while mac80211 still holds it; impact is host-kernel heap corruption, not a VM, IOMMU, or sandbox escape.\nC:H - ieee80211_free_hw() kfree's the ext PHY's still-registered wiphy bands and wiphy_free()s the hw while cfg80211 and mt7915_thermal_get_cur_throttle_state() still dereference that phy via cdev->devdata, a UAF read primitive.\nI:H - The leftover ext-PHY object is written by mt7915_thermal_set_cur_throttle_state() (phy->cdev_state and mt7915_mcu_set_thermal_throttling) and by mac80211 workqueues never torn down by ieee80211_unregister_hw(), enabling UAF writes and control-flow hijack.\nA:H - ieee80211_free_hw() without ieee80211_unregister_hw() leaves mac80211 workqueues, inetaddr notifiers, and the default wlan vif running against freed ieee80211_local, which oopses or panics on the next access."
    }
  }
}