CVE-2026-98200

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show() nsensor->current_state is dynamically replaced as the sensor's state changes. update_numeric_sensor_from_wobj() does this by freeing the old string and installing a new one: if (strcmp(trimmed, nsensor->current_state)) { new_string = hp_wmi_strdup(dev, trimmed); if (new_string) { devm_kfree(dev, nsensor->current_state); nsensor->current_state = new_string; } } This function is only ever called from hp_wmi_update_info() while state->lock is held, so the free-and-replace itself is properly serialized against concurrent updates. fungible_show(), however, reads the same pointer after the lock has already been dropped: err = hp_wmi_update_info(state, info); if (err) return err; switch (prop) { ... case HP_WMI_PROPERTY_CURRENT_STATE: seq_printf(seqf, "%s\n", nsensor->current_state); break; hp_wmi_update_info() takes state->lock internally and releases it before returning, so by the time fungible_show() dereferences nsensor->current_state in seq_printf(), no lock is held. Two processes reading a sensor's current_state debugfs entry at overlapping times (or one reading it while another read of the same sensor triggers a refresh) can race: one thread's seq_printf() can be part-way through printing the string at the moment another thread's call into update_numeric_sensor_from_wobj() frees it with devm_kfree() and installs a new pointer, causing a use-after-free read. Take state->lock around the read in fungible_show() as well, so it can never run concurrently with the free-and-replace in update_numeric_sensor_from_wobj().

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-06 09:18:05.747000

Last modified

2026-10-19 10:18:20.623000

View original CVE JSON

{
  "id": "CVE-2026-98200",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:05.747",
  "lastModified": "2026-10-19T10:18:20.623",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (hp-wmi-sensors) Fix use-after-free in fungible_show()\n\nnsensor->current_state is dynamically replaced as the sensor's state\nchanges. update_numeric_sensor_from_wobj() does this by freeing the\nold string and installing a new one:\n\n\tif (strcmp(trimmed, nsensor->current_state)) {\n\t\tnew_string = hp_wmi_strdup(dev, trimmed);\n\t\tif (new_string) {\n\t\t\tdevm_kfree(dev, nsensor->current_state);\n\t\t\tnsensor->current_state = new_string;\n\t\t}\n\t}\n\nThis function is only ever called from hp_wmi_update_info() while\nstate->lock is held, so the free-and-replace itself is properly\nserialized against concurrent updates.\n\nfungible_show(), however, reads the same pointer after the lock has\nalready been dropped:\n\n\terr = hp_wmi_update_info(state, info);\n\tif (err)\n\t\treturn err;\n\n\tswitch (prop) {\n\t...\n\tcase HP_WMI_PROPERTY_CURRENT_STATE:\n\t\tseq_printf(seqf, \"%s\\n\", nsensor->current_state);\n\t\tbreak;\n\nhp_wmi_update_info() takes state->lock internally and releases it\nbefore returning, so by the time fungible_show() dereferences\nnsensor->current_state in seq_printf(), no lock is held. Two\nprocesses reading a sensor's current_state debugfs entry at\noverlapping times (or one reading it while another read of the same\nsensor triggers a refresh) can race: one thread's seq_printf() can\nbe part-way through printing the string at the moment another\nthread's call into update_numeric_sensor_from_wobj() frees it with\ndevm_kfree() and installs a new pointer, causing a use-after-free\nread.\n\nTake state->lock around the read in fungible_show() as well, so it\ncan never run concurrently with the free-and-replace in\nupdate_numeric_sensor_from_wobj()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/hwmon/hp-wmi-sensors.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "23902f98f8d4811ab84dde6419569a5b374f8122",
              "lessThan": "b6b2a638aa36c441b2c8d0b6bd8ed2bb9701e795",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "23902f98f8d4811ab84dde6419569a5b374f8122",
              "lessThan": "f59ecfd2c58bace39538f3fff7f43788b3fdb539",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "23902f98f8d4811ab84dde6419569a5b374f8122",
              "lessThan": "72c85149794a1ccf8d718ffed1521106b5d31968",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "23902f98f8d4811ab84dde6419569a5b374f8122",
              "lessThan": "9c1e65bc79ff104914b11e6ad972139296ec86fe",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "23902f98f8d4811ab84dde6419569a5b374f8122",
              "lessThan": "e6cb0b4d4ecb8e71fd2200d907ab2e9663356f69",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/hwmon/hp-wmi-sensors.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.5",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.5",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.54",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/72c85149794a1ccf8d718ffed1521106b5d31968",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9c1e65bc79ff104914b11e6ad972139296ec86fe",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b6b2a638aa36c441b2c8d0b6bd8ed2bb9701e795",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e6cb0b4d4ecb8e71fd2200d907ab2e9663356f69",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f59ecfd2c58bace39538f3fff7f43788b3fdb539",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}