{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-64277",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-64277"
  ],
  "published": "2026-07-25T08:51:45Z",
  "summary": "Input: synaptics-rmi4 - bound the F3A keymap to the GPIO count",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nInput: synaptics-rmi4 - bound the F3A keymap to the GPIO count\n\nrmi_f3a_initialize() takes the GPIO count from the device query register\n(f3a->gpio_count = buf & RMI_F3A_GPIO_COUNT, range 0..127).\nrmi_f3a_map_gpios() then allocates gpio_key_map with\nmin(gpio_count, TRACKSTICK_RANGE_END) == at most 6 entries, but\nrmi_f3a_attention() iterates the full gpio_count and dereferences\ngpio_key_map[i], and input->keycodemax is set to the full gpio_count\nwhile input->keycode points at the 6-entry allocation.\n\nA device that reports gpio_count > 6 therefore causes an out-of-bounds\nread of gpio_key_map[] on every attention interrupt, and out-of-bounds\naccesses through the input core's default keymap ioctls: EVIOCGKEYCODE\nreads past the buffer (leaking adjacent slab memory to user space) and\nEVIOCSKEYCODE writes a caller-controlled value past it, for any process\nable to open the evdev node, since input_default_getkeycode() and\ninput_default_setkeycode() only bound the index against keycodemax.\n\nSize the keymap for the full gpio_count. The mapping loop is unchanged:\nit still assigns only the first min(gpio_count, TRACKSTICK_RANGE_END)\nentries; the remaining slots stay KEY_RESERVED (devm_kcalloc zero-fills)\nand are skipped when reporting.",
  "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": "6.1.178",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-64277"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/502ad7caaa1a445b734c827fa256e5311df67e3d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3480e24bc4e178aaa009edb25b6ee12df199e210"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/35ed74d32d8260bdfb14a94caf402bf0866bdeec"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ba57f430328534501962d60d651e385ffd7af9ca"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/850117b637bcb1dcc14be0cf09ac819a8707b42c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8db211aed83733073b0814adaeeab61d4521474e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/64fb0e1161ccc6b9e48b8df61f07d3c34c01ec42"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/57c10915f2c16c90e0d46ad00876bf39ece40fc2"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:24:08Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The highest-severity defensible path is local: a process that can open the affected RMI touchpad's evdev node can invoke the vulnerable keymap ioctls. A malicious USB RMI device is also a physical trigger, but the local ioctl path is more severe.\nAC:L - On a vulnerable device reporting more than six GPIOs, selecting any keymap index from 6 through gpio_count-1 deterministically accesses beyond the allocation. No race or condition outside the attacker's control is required.\nPR:L - The evdev keymap ioctl path has no capability or authentication check; only ordinary device-node access controls apply. An unprivileged user with seat, ACL, or input-device access can exploit it without administrative capabilities.\nUI:N - The attacker directly issues EVIOCGKEYCODE or EVIOCSKEYCODE after opening the node. No action by another user is required.\nS:U - Exploitation compromises the host kernel within the same security authority. It does not inherently cross a VM, IOMMU, or other separate security boundary.\nC:H - EVIOCGKEYCODE can disclose successive 16-bit words across as much as 242 bytes beyond the six-entry keymap, exposing adjacent slab contents and potentially kernel pointers. The accompanying corruption can also support stronger disclosure primitives.\nI:H - EVIOCSKEYCODE provides indexed, caller-controlled 16-bit writes throughout the out-of-bounds range. This heap corruption can overwrite adjacent pointers or control data and plausibly enable kernel code execution.\nA:H - The controlled heap overwrite can corrupt adjacent slab objects and cause a kernel oops or panic, while device attention interrupts repeatedly exercise the out-of-bounds read. The failure can be triggered repeatedly without victim interaction."
    }
  }
}