UnratedFix available

hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer adm1266_pmbus_block_xfer() copies the device-supplied block payload into the caller-provided buffer using the device-supplied length: memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]); The helper does not know how large data_r is and trusts the device to return at most one record's worth of bytes. adm1266_nvmem_read_blackbox() violates that contract: it advances read_buff inside data->dev_mem in ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns more than 64 bytes on the trailing record (read_buff offset 1984 in the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes before the post-call if (ret != ADM1266_BLACKBOX_SIZE) return -EIO; can reject the response. Contain the fix in the caller without changing the helper signature: read each record into a 255-byte local bounce buffer that matches the helper's maximum output, validate the returned length, and only then copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.

Products: Kernel
Affected versions: Not specified
Fixed versions: 5.10.258, 5.15.209, 6.1.175, 6.12.92, 6.18.34, 6.6.142, 7.0.11
CVEs: CVE-2026-64085
Confirmed fixed CVEs: Not specified
Updated in this feed: 3 Nov 2026, 19:58 UTC · Revision 1

Source evidence

hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer

core-osv · Original source

Published 19 Jul 2026, 15:39 UTC

osv:CVE-2026-64085

Kernel

Fixed versions: 5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11

Complete source record

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  "url": "https://osv.dev/vulnerability/CVE-2026-64085",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) bounce blackbox records through a protocol-sized buffer adm1266_pmbus_block_xfer() copies the device-supplied block payload into the caller-provided buffer using the device-supplied length: memcpy(data_r, &msgs[1].buf[1], msgs[1].buf[0]); The helper does not know how large data_r is and trusts the device to return at most one record's worth of bytes. adm1266_nvmem_read_blackbox() violates that contract: it advances read_buff inside data->dev_mem in ADM1266_BLACKBOX_SIZE (64-byte) strides while the helper is willing to write up to ADM1266_PMBUS_BLOCK_MAX (255) bytes. A device that returns more than 64 bytes on the trailing record (read_buff offset 1984 in the 2048-byte dev_mem allocation) overflows dev_mem by up to 191 bytes before the post-call if (ret != ADM1266_BLACKBOX_SIZE) return -EIO; can reject the response. Contain the fix in the caller without changing the helper signature: read each record into a 255-byte local bounce buffer that matches the helper's maximum output, validate the returned length, and only then copy exactly ADM1266_BLACKBOX_SIZE bytes into the dev_mem slot.",
    "evidence": "osv:CVE-2026-64085",
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      "modified": "2026-10-28T02:30:32.148589607Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/43cae21424ff8e33894a0f86c6b80b840c049fd7",
        "https://git.kernel.org/stable/c/6098634cfa711f11a8d65368dc51ec8f7c8241ba",
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        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64085.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64085",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
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    "related_cves": [
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  "source_id": "core-osv",
  "document_id": 498857,
  "published_at": "2026-07-19T15:39:56.067+00:00"
}