CVE-2026-89486

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ipmi: Fix use-after-free of cmd_rcvr in _ipmi_destroy_user() Commit 9e91f8a6c868 ("ipmi:msghandler: Remove srcu for the ipmi_interfaces list") dropped the synchronize_rcu() between unlinking the command receivers from intf->cmd_rcvrs and freeing them, updating only the comment that explains why the barrier is needed. The cmd_rcvrs list is still traversed under plain RCU: find_cmd_rcvr() walks it inside rcu_read_lock(), and handle_ipmb_get_msg_cmd() borrows rcvr->user from that lookup within the same read-side section. Without the grace period, _ipmi_destroy_user() can kfree() a cmd_rcvr while a reader still holds a pointer to it, causing a use-after-free. The rework only made srcu unnecessary for the interfaces list; the cmd_rcvrs list still relies on plain RCU. Restore the synchronize_rcu() before freeing the receivers.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

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

Published

2026-09-11 20:19:30.297000

Last modified

2026-10-19 09:17:42.180000

View original CVE JSON

{
  "id": "CVE-2026-89486",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:30.297",
  "lastModified": "2026-10-19T09:17:42.180",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipmi: Fix use-after-free of cmd_rcvr in _ipmi_destroy_user()\n\nCommit 9e91f8a6c868 (\"ipmi:msghandler: Remove srcu for the\nipmi_interfaces list\") dropped the synchronize_rcu() between unlinking\nthe command receivers from intf->cmd_rcvrs and freeing them, updating\nonly the comment that explains why the barrier is needed.\n\nThe cmd_rcvrs list is still traversed under plain RCU: find_cmd_rcvr()\nwalks it inside rcu_read_lock(), and handle_ipmb_get_msg_cmd() borrows\nrcvr->user from that lookup within the same read-side section. Without\nthe grace period, _ipmi_destroy_user() can kfree() a cmd_rcvr while a\nreader still holds a pointer to it, causing a use-after-free.\n\nThe rework only made srcu unnecessary for the interfaces list; the\ncmd_rcvrs list still relies on plain RCU. Restore the synchronize_rcu()\nbefore freeing the receivers."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/char/ipmi/ipmi_msghandler.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "9e91f8a6c8688e27f4ccce7db457da87d6458836",
              "lessThan": "3088e41292fecf132f85f79af5ee4d620b9ff1b4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "9e91f8a6c8688e27f4ccce7db457da87d6458836",
              "lessThan": "5dc0b2a9af95a97861c1bffaf1687a3173e395c5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "9e91f8a6c8688e27f4ccce7db457da87d6458836",
              "lessThan": "05ec76cfbce653e07cec19b9b8b20e33449d5d87",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/char/ipmi/ipmi_msghandler.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/05ec76cfbce653e07cec19b9b8b20e33449d5d87",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3088e41292fecf132f85f79af5ee4d620b9ff1b4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5dc0b2a9af95a97861c1bffaf1687a3173e395c5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}