CVE-2026-98826 (GCVE-0-2026-98826)
Vulnerability from cvelistv5
Published
2026-10-18 15:49
Modified
2026-10-19 09:26
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: rtc: ac100: Fix clock provider use-after-free on probe failure ac100_rtc_register_clks() registers the RTC-32k clock with clk_hw_register_fixed_rate() and the clock provider with of_clk_add_hw_provider(). Neither is device managed, and both are released only from ac100_rtc_remove(). The driver core does not call remove() when probe() fails: really_probe() reaches probe_failed below the device_remove() call and goes straight to releasing the device's managed resources. ac100_rtc_probe() ends with return devm_rtc_register_device(chip->rtc); so if that fails after the clocks have been registered, the provider is left on the global of_clk_providers list holding chip->clk_data, which was allocated with devm_kzalloc() and is freed while probe() unwinds. A later lookup on this device tree node then reads freed memory in of_clk_hw_onecell_get(). Consumers that do exactly that exist in tree: the wifi power sequence nodes on sun8i-a83t-bananapi-m3 and sun8i-a83t-cubietruck-plus take <&ac100_rtc 1>, and the sun9i-a80 boards route osc32k through <&ac100_rtc 0>. The window is narrow, as devm_rtc_register_device() can only fail with -ENOMEM here, but the provider is left dangling whenever it does. The RTC-32k clock is leaked on the same path. Since clk_core_lookup() searches a global list that is not scoped per device, __clk_register() rejects the duplicate name with -EEXIST, so the leak also makes a later probe of the same device fail. The error path that returns -EINVAL when the ADDA 4M parent clock cannot be found leaks the RTC-32k clock in the same way. No provider has been registered at that point, so that one is a leak rather than a use-after-free. Register both with devm_clk_hw_register_fixed_rate() and devm_of_clk_add_hw_provider() so that they are released whenever the device goes away, on a failed probe as well as on unbind. Devres releases in reverse order of acquisition, so the provider is removed before chip->clk_data is freed, and the clkout children are now unregistered before their parent rather than after it. ac100_rtc_unregister_clks() and the remove callback then have nothing left to do and are removed.
References
Impacted products
Vendor Product Version
Linux Linux Version: d00a18a42c1483924de086ddfb0efe8da1dba3ac
Version: d00a18a42c1483924de086ddfb0efe8da1dba3ac
Version: d00a18a42c1483924de086ddfb0efe8da1dba3ac
Version: d00a18a42c1483924de086ddfb0efe8da1dba3ac
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/rtc/rtc-ac100.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "12bcd20d76703ee2baf52224d287b7fea096b12f",
              "status": "affected",
              "version": "d00a18a42c1483924de086ddfb0efe8da1dba3ac",
              "versionType": "git"
            },
            {
              "lessThan": "9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8",
              "status": "affected",
              "version": "d00a18a42c1483924de086ddfb0efe8da1dba3ac",
              "versionType": "git"
            },
            {
              "lessThan": "55ca60ba336632349f7c4585d22ba74ae355b7ce",
              "status": "affected",
              "version": "d00a18a42c1483924de086ddfb0efe8da1dba3ac",
              "versionType": "git"
            },
            {
              "lessThan": "fcf0b58e976e83adf246b014518e49c662b96f5e",
              "status": "affected",
              "version": "d00a18a42c1483924de086ddfb0efe8da1dba3ac",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/rtc/rtc-ac100.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.9"
            },
            {
              "lessThan": "4.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtc: ac100: Fix clock provider use-after-free on probe failure\n\nac100_rtc_register_clks() registers the RTC-32k clock with\nclk_hw_register_fixed_rate() and the clock provider with\nof_clk_add_hw_provider(). Neither is device managed, and both are\nreleased only from ac100_rtc_remove(). The driver core does not call\nremove() when probe() fails: really_probe() reaches probe_failed below\nthe device_remove() call and goes straight to releasing the device\u0027s\nmanaged resources.\n\nac100_rtc_probe() ends with\n\n\treturn devm_rtc_register_device(chip-\u003ertc);\n\nso if that fails after the clocks have been registered, the provider is\nleft on the global of_clk_providers list holding chip-\u003eclk_data, which\nwas allocated with devm_kzalloc() and is freed while probe() unwinds. A\nlater lookup on this device tree node then reads freed memory in\nof_clk_hw_onecell_get(). Consumers that do exactly that exist in tree:\nthe wifi power sequence nodes on sun8i-a83t-bananapi-m3 and\nsun8i-a83t-cubietruck-plus take \u003c\u0026ac100_rtc 1\u003e, and the sun9i-a80 boards\nroute osc32k through \u003c\u0026ac100_rtc 0\u003e. The window is narrow, as\ndevm_rtc_register_device() can only fail with -ENOMEM here, but the\nprovider is left dangling whenever it does.\n\nThe RTC-32k clock is leaked on the same path. Since clk_core_lookup()\nsearches a global list that is not scoped per device, __clk_register()\nrejects the duplicate name with -EEXIST, so the leak also makes a later\nprobe of the same device fail.\n\nThe error path that returns -EINVAL when the ADDA 4M parent clock cannot\nbe found leaks the RTC-32k clock in the same way. No provider has been\nregistered at that point, so that one is a leak rather than a\nuse-after-free.\n\nRegister both with devm_clk_hw_register_fixed_rate() and\ndevm_of_clk_add_hw_provider() so that they are released whenever the\ndevice goes away, on a failed probe as well as on unbind. Devres\nreleases in reverse order of acquisition, so the provider is removed\nbefore chip-\u003eclk_data is freed, and the clkout children are now\nunregistered before their parent rather than after it.\nac100_rtc_unregister_clks() and the remove callback then have nothing\nleft to do and are removed."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:26:19.030Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/12bcd20d76703ee2baf52224d287b7fea096b12f"
        },
        {
          "url": "https://git.kernel.org/stable/c/9cff19ddd7f90c1f572a0f83cfc41de8f8dcbcd8"
        },
        {
          "url": "https://git.kernel.org/stable/c/55ca60ba336632349f7c4585d22ba74ae355b7ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/fcf0b58e976e83adf246b014518e49c662b96f5e"
        }
      ],
      "title": "rtc: ac100: Fix clock provider use-after-free on probe failure",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98826",
    "datePublished": "2026-10-18T15:49:19.709Z",
    "dateReserved": "2026-09-25T10:25:14.372Z",
    "dateUpdated": "2026-10-19T09:26:19.030Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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