{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-64084",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-64084"
  ],
  "published": "2026-07-19T15:41:06Z",
  "summary": "hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR\n\nadm1266_gpio_get_multiple() iterates the PDIO portion of the\ncaller-supplied mask using\n\n\tfor_each_set_bit_from(gpio_nr, mask,\n\t\t\t      ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) {\n\t\t...\n\t}\n\nwhere ADM1266_PDIO_STATUS is the PMBus command code (0xE9, i.e. 233),\nnot the number of PDIO pins.  The intended upper bound is\nADM1266_GPIO_NR + ADM1266_PDIO_NR = 25.\n\ngpiolib hands in a mask sized for gc.ngpio (= 25 bits on this chip),\nso the iteration walks find_next_bit() up to 242, reading up to 217\nextra bits (a handful of unsigned-long words: four on 64-bit, seven\non 32-bit) of whatever lives past the end of the mask in the\ncaller's stack.  Any incidental set bit in that range then drives a\nset_bit(gpio_nr, bits) call that writes past the end of the\ncaller-supplied bits array too -- both out-of-bounds.\n\nSubstitute ADM1266_PDIO_NR for the constant so the scan stops at the\nlast real PDIO bit.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/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": "6.1.175",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-64084"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d0593e15fdeb56048a72c5c6e720f702759d0ccd"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/17cee2f59029039416e8f6303050038eb59ba149"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/299efd14c2eda7e5fd40025e54addd4151a01081"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4d1da9a6be5a8156c532d571c2ed237169f99244"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b96c7f0bc0713dc6403912f6527d4ff9168d6fe6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fa7ca363069a70b0d1aa51e8892e3095fe2ac1ec"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2aef8f08c479f4cbc83e1e6b19d1c94d4dd24f17"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d7834d92251baade796812876e95555e2066fa9f"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The bug is only reachable through the GPIO character-device ioctl path (gpiolib \u2192 adm1266_gpio_get_multiple), which requires local access to /dev/gpiochip* on a system with an ADM1266 present on I2C; it is not triggered by network packets or physical bus access.\nAC:L - Any caller who can request ADM1266 PDIO lines and issue a multi-line GET_VALUES ioctl reliably enters the flawed loop; no race or victim state beyond attacker-controlled ioctl parameters is required.\nPR:L - Exploitation requires only a local account that can open the GPIO char device and request lines (e.g. root, gpio group membership, or a BMC service account with device access), not full init-namespace CAP_SYS_ADMIN; this is plausible on embedded/BMC deployments where ADM1266 is used.\nUI:N - Once the attacker has GPIO char-device access, triggering the bug is a single ioctl with no additional victim interaction.\nS:U - Impact is kernel stack memory corruption and potential privilege escalation within the same kernel security domain; it does not cross a VM, IOMMU, or sandbox boundary.\nC:H - The flawed loop performs out-of-bounds reads of up to ~217 bits beyond the 25-bit mask into adjacent kernel stack memory, constituting kernel memory disclosure per OOB-read guidance.\nI:H - Incidental set bits found during the out-of-bounds mask scan drive set_bit() writes past the end of the caller-supplied bits array, causing out-of-bounds kernel stack writes that could be leveraged for control-flow hijacking.\nA:H - Stack corruption from the out-of-bounds writes can cause kernel oops, panic, or hang, satisfying the kernel guidance that memory-corruption bugs warrant High availability impact."
    }
  }
}