{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "5bc493bf0c37c157bf2eb364e55a1c6f8bc43a69"
            },
            {
              "fixed": "6cf600b276a55a6481462830607a611f32e737c0"
            },
            {
              "fixed": "5bd8e897ecf558507142f4553e4526adfc1d6482"
            },
            {
              "fixed": "00268f9452d2a0d660aa9c1bb0ca07a994af6a4f"
            }
          ],
          "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": "6.18.46"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74738.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nregmap: sdw-mbq: don't call an unset readable_reg callback\n\nregmap_sdw_mbq_poll_busy() decides whether to poll the Function Busy bit\nby calling ctx-\u003ereadable_reg(), which is a straight copy of\nconfig-\u003ereadable_reg. That callback is optional: regmap_readable() treats\na NULL -\u003ereadable_reg as \"every register is readable\", and drivers rely on\nthat. es9356 and tac5xx2-sdw both build an MBQ regmap without one.\n\nSince commit ca1b11b36d82 (\"regmap: sdw-mbq: Allow defers on undeferrable\ncontrols\") the poll runs on every -ENODATA, not only for Controls the\ndriver marked deferrable, so any of those devices answering\nCOMMAND_IGNORED takes the kernel through a NULL function pointer.\n\nTreat a missing callback the way the rest of regmap does and poll.",
  "id": "CVE-2026-74738",
  "modified": "2026-08-28T11:30:26.881646303Z",
  "published": "2026-08-26T14:36:51.136Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/00268f9452d2a0d660aa9c1bb0ca07a994af6a4f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5bd8e897ecf558507142f4553e4526adfc1d6482"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6cf600b276a55a6481462830607a611f32e737c0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74738.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74738"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "regmap: sdw-mbq: don't call an unset readable_reg callback"
}