{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "132d44dc6966c1cf841ffe0f6f048165687e870b"
            },
            {
              "fixed": "3394e0b3328422431cadaf314fa58d3717ed4936"
            },
            {
              "fixed": "3bceb26dfaf7ba805b459e41c1d0ba916862dade"
            },
            {
              "fixed": "91bc6767a4f55dc470d8a56b55b9f2ea09094efe"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.14.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64502.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices\n\nad_sigma_delta_clear_pending_event() falls through to the status register\nread path for devices with has_registers = false and no rdy_gpiod. For\nsuch devices, ad_sd_read_reg() skips the address byte entirely and clocks\nraw MISO bytes with no address phase — making it byte-for-byte identical\nto reading conversion data. If a pending conversion result is present,\nthis partially consumes it and corrupts the data stream for the subsequent\nad_sd_read_reg() call in ad_sigma_delta_single_conversion().\n\nFurthermore, with num_resetclks = 0 on these devices, data_read_len\nevaluates to 0. If the clocked byte has bit 7 clear, pending_event is set\nand the code attempts memset(data + 2, 0xff, 0 - 1), overflowing to\nSIZE_MAX and corrupting the heap.\n\nFix by returning 0 immediately when neither rdy_gpiod nor has_registers\nis set. This is safe for all current registerless devices: ad7191 and\nad7780 (with powerdown GPIO) are reset between conversions by CS\ndeassertion, so there is no stale result to drain; ad7780 (without\npowerdown GPIO) and max11205 are continuously-converting and cycle ~DRDY\nat the output data rate regardless of whether the previous result was\nread, so the next falling edge fires naturally.\n\nA future registerless device that holds ~DRDY asserted until data is read\nwould be broken by this early return and would require either\nnum_resetclks set or a rdy-gpio.\n\nThe same heap corruption is reachable on any device with rdy_gpiod set\nbut num_resetclks = 0: if the GPIO indicates a pending event, the drain\npath executes memset(data + 2, 0xff, 0 - 1) regardless of has_registers.\nAdd an explicit data_read_len == 0 guard after the pending event check;\nthe stale result is then consumed by the first ad_sd_read_reg() call in\nad_sigma_delta_single_conversion().",
  "id": "CVE-2026-64502",
  "modified": "2026-07-28T03:55:45.519880600Z",
  "published": "2026-07-25T08:51:57.477Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3394e0b3328422431cadaf314fa58d3717ed4936"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3bceb26dfaf7ba805b459e41c1d0ba916862dade"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/91bc6767a4f55dc470d8a56b55b9f2ea09094efe"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64502.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64502"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices"
}