{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  platform/x86/amd/hsmp: Reject negative power cap writes in hwmon  hsmp_hwmon_write() takes the user-supplied hwmon value as a signed long and assigns \"val / MICROWATT_PER_MILLIWATT\" to msg.args[0], which is a __u32.  MICROWATT_PER_MILLIWATT is an unsigned long, so a negative write to power1_cap (e.g. \"echo -1 \u003e power1_cap\") is first converted to a huge unsigned value by the division and then stored into the u32 argument.  As a result a nonsensical, multi-gigawatt socket power limit is sent to the SMU via HSMP_SET_SOCKET_POWER_LIMIT instead of the write being rejected.  Reject negative values with -EINVAL before the conversion.  Tested with HSMP enabled:    CAP=$(dirname $(grep -l amd_hsmp_hwmon \\         /sys/class/hwmon/hwmon*/name | head -1))/power1_cap    # negative write   echo -1000000 \u003e $CAP ; echo \"ret=$?\"   # valid positive write must still work   echo 400000000 \u003e $CAP ; echo \"ret=$?\"  Before:   # echo -1000000 \u003e $CAP ; echo \"ret=$?\"   ret=0                             \u003c- accepted; bogus limit sent to SMU   # echo 400000000 \u003e $CAP ; echo \"ret=$?\"   ret=0  After:   # echo -1000000 \u003e $CAP ; echo \"ret=$?\"   bash: echo: write error: Invalid argument   ret=1                             \u003c- rejected with -EINVAL   # echo 400000000 \u003e $CAP ; echo \"ret=$?\"   ret=0                             \u003c- valid write still works",
  "id": "DEBIAN-CVE-2026-90136",
  "modified": "2026-09-18T04:47:30.322478364Z",
  "published": "2026-09-17T17:17:06.173Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-90136"
    }
  ],
  "upstream": [
    "CVE-2026-90136"
  ]
}