{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ba92222ed63a12d09120df9b92f56cc990abac19"
            },
            {
              "fixed": "cc111696ef420f6bb552b2526530067977f0b406"
            },
            {
              "fixed": "f96a719d9f8a797105ec5cacf568ab128e33391f"
            },
            {
              "fixed": "deffad5bb4f8b4f09e46252f24754ddc9960b244"
            },
            {
              "fixed": "14429dc1c756c35e106f01ff09cadccb82f5531d"
            },
            {
              "fixed": "b6cb47e186abba85a3b08aa3023067ab82577286"
            },
            {
              "fixed": "19b783335d62e7a2367436a6e1f1b37da1878360"
            },
            {
              "fixed": "aa1944b52d6492c48bdd17046578aa0d953546e6"
            },
            {
              "fixed": "d99607c888f26e8a4e9fe9772860cef4aff86bb4"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.1.0"
            },
            {
              "fixed": "5.10.265"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.151"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.103"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.44"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74463.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: jz4780: Cache host clock rate at probe to prevent CCF prepare_lock deadlock\n\nFix a severe AB/BA deadlock between the Common Clock Framework (CCF)\nand the I2C adapter lock, which triggers when an I2C-controlled clock\ngenerator client (like the Si5351) is registered or modified under the CCF.\n\nDuring an i2c client clock (generator) frequency change, the CCF acquires its global\n'prepare_lock' mutex and the driver calls i2c_transfer() to update the client's\nchip registers, stalling for the adapter's I2C bus lock.\n\nConcurrently, an independent, parallel transfer on the same bus (e.g., a GPIO\nexpander handling LEDs) can hold the I2C adapter lock. Inside this parallel\ntransfer path, jz4780_i2c_set_speed() calls clk_get_rate() on the host\ncontroller's input clock to calculate bus timings. This call attempts to acquire\nthe blocked CCF 'prepare_lock', creating a circular dependency that freezes\nthe system.\n\nThe jz4780 host controller clock itself is static and never changes at runtime.\n\nHowever, calling clk_get_rate() inside the active transfer path introduces\nan unnecessary dependency on the CCF internal locks.\n\nEliminate this synchronous clk_get_rate() call from the active transfer\npath by caching the static host peripheral clock rate once - inside the private\njz4780_i2c structure during jz4780_i2c_probe(). Update jz4780_i2c_set_speed()\nto use this cached value, safely decoupling active I2C transactions from the\nCCF internal locks without any risk of stale timings.\n\nAssisted-by web based Google AI (pinpointing the bug and writing the message).",
  "id": "CVE-2026-74463",
  "modified": "2026-08-21T03:30:41.092827361Z",
  "published": "2026-08-15T12:27:03.176Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/14429dc1c756c35e106f01ff09cadccb82f5531d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19b783335d62e7a2367436a6e1f1b37da1878360"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aa1944b52d6492c48bdd17046578aa0d953546e6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b6cb47e186abba85a3b08aa3023067ab82577286"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc111696ef420f6bb552b2526530067977f0b406"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d99607c888f26e8a4e9fe9772860cef4aff86bb4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/deffad5bb4f8b4f09e46252f24754ddc9960b244"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f96a719d9f8a797105ec5cacf568ab128e33391f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74463.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74463"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "i2c: jz4780: Cache host clock rate at probe to prevent CCF prepare_lock deadlock"
}