CVE-2026-98848 (GCVE-0-2026-98848)
Vulnerability from cvelistv5
Published
2026-10-18 15:50
Modified
2026-10-21 12:57
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: rtc: ac100: Assign .num before accessing .hws Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by") annotated the hws member of 'struct clk_hw_onecell_data' with __counted_by, which informs the bounds sanitizer (UBSAN_BOUNDS) about the number of elements in .hws[], so that it can warn when .hws[] is accessed out of bounds. As noted in that change, the __counted_by member must be initialized with the number of elements before the first array access happens, otherwise there will be a warning from each access prior to the initialization because the number of elements is zero. This occurs in ac100_rtc_register_clks() due to .num being assigned only after every clkout clock has been stored in .hws[]. With CONFIG_UBSAN_BOUNDS and a compiler that implements __counted_by (GCC 15.1+ or Clang 20.1+), this triggers an array-index-out-of-bounds report during probe, and with CONFIG_UBSAN_TRAP the first store traps. Initialize .num with AC100_CLKOUT_NUM, the number of elements .hws[] was allocated with, right after the allocation. That is the value the loop counter ends up at on the success path anyway, so the provider's behaviour is unchanged.
References
Impacted products
Vendor Product Version
Linux Linux Version: f316cdff8d677db9ad9c90acb44c4cd535b0ee27
Version: f316cdff8d677db9ad9c90acb44c4cd535b0ee27
Version: f316cdff8d677db9ad9c90acb44c4cd535b0ee27
Version: f316cdff8d677db9ad9c90acb44c4cd535b0ee27
Version: f316cdff8d677db9ad9c90acb44c4cd535b0ee27
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "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": "e77c5fc1f39fdb06ecd1f55b101eea1e1db2ffef",
              "status": "affected",
              "version": "f316cdff8d677db9ad9c90acb44c4cd535b0ee27",
              "versionType": "git"
            },
            {
              "lessThan": "6bb55381daf1a1bed0657189a1396e7467712525",
              "status": "affected",
              "version": "f316cdff8d677db9ad9c90acb44c4cd535b0ee27",
              "versionType": "git"
            },
            {
              "lessThan": "160619b38707241e22569f9c983a4b3d0890996a",
              "status": "affected",
              "version": "f316cdff8d677db9ad9c90acb44c4cd535b0ee27",
              "versionType": "git"
            },
            {
              "lessThan": "ad1bf77039cba83373bf1eff3784655e3e3ed2ab",
              "status": "affected",
              "version": "f316cdff8d677db9ad9c90acb44c4cd535b0ee27",
              "versionType": "git"
            },
            {
              "lessThan": "6a4117eee82dd85f11bf898bf66026764011eeb6",
              "status": "affected",
              "version": "f316cdff8d677db9ad9c90acb44c4cd535b0ee27",
              "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": "6.6"
            },
            {
              "lessThan": "6.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "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": "6.6.160",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrtc: ac100: Assign .num before accessing .hws\n\nCommit f316cdff8d67 (\"clk: Annotate struct clk_hw_onecell_data with\n__counted_by\") annotated the hws member of \u0027struct clk_hw_onecell_data\u0027\nwith __counted_by, which informs the bounds sanitizer (UBSAN_BOUNDS)\nabout the number of elements in .hws[], so that it can warn when .hws[]\nis accessed out of bounds. As noted in that change, the __counted_by\nmember must be initialized with the number of elements before the first\narray access happens, otherwise there will be a warning from each access\nprior to the initialization because the number of elements is zero.\nThis occurs in ac100_rtc_register_clks() due to .num being assigned only\nafter every clkout clock has been stored in .hws[]. With\nCONFIG_UBSAN_BOUNDS and a compiler that implements __counted_by (GCC\n15.1+ or Clang 20.1+), this triggers an array-index-out-of-bounds report\nduring probe, and with CONFIG_UBSAN_TRAP the first store traps.\n\nInitialize .num with AC100_CLKOUT_NUM, the number of elements .hws[] was\nallocated with, right after the allocation. That is the value the loop\ncounter ends up at on the success path anyway, so the provider\u0027s\nbehaviour is unchanged."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:57:28.688Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e77c5fc1f39fdb06ecd1f55b101eea1e1db2ffef"
        },
        {
          "url": "https://git.kernel.org/stable/c/6bb55381daf1a1bed0657189a1396e7467712525"
        },
        {
          "url": "https://git.kernel.org/stable/c/160619b38707241e22569f9c983a4b3d0890996a"
        },
        {
          "url": "https://git.kernel.org/stable/c/ad1bf77039cba83373bf1eff3784655e3e3ed2ab"
        },
        {
          "url": "https://git.kernel.org/stable/c/6a4117eee82dd85f11bf898bf66026764011eeb6"
        }
      ],
      "title": "rtc: ac100: Assign .num before accessing .hws",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98848",
    "datePublished": "2026-10-18T15:50:47.105Z",
    "dateReserved": "2026-09-25T10:25:14.373Z",
    "dateUpdated": "2026-10-21T12:57:28.688Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.