CVE-2026-98268

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: perf: Fix null pointer access in is_include_guest_event() A typical module unload occurring event when there is an active perf connection leads to freeing of the pmu pointer. The call log is something like: .. __pmu_detach_event pmu_detach_event pmu_detach_events perf_pmu_unregister .. __pmu_detach_event() sets event->pmu to null. When the perf connection finally is closed, the following stack trace is observed: Oops: general protection fault, kernel NULL pointer dereference ... RIP: 0010:_free_event+0x3e/0x370 ... Call Trace: ... perf_event_release_kernel+0x260/0x2d0 perf_release+0x12/0x20 A call to mediated_pmu_unaccount_event() inside _free_event() is the root cause of this crash. Adding a check inside is_include_guest_event() ensures we don't accidentally access a null pmu ptr. In addition to this, we will now call mediated_pmu_unaccount_event() before clearing the pmu ptr so that nr_include_guest_events counts are maintained correctly.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-10-06 09:18:16.227000

Last modified

2026-10-19 10:18:28.043000

View original CVE JSON

{
  "id": "CVE-2026-98268",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:16.227",
  "lastModified": "2026-10-19T10:18:28.043",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Fix null pointer access in is_include_guest_event()\n\nA typical module unload occurring event when there is an active perf\nconnection leads to freeing of the pmu pointer. The call log is something\nlike:\n ..\n __pmu_detach_event\n pmu_detach_event\n pmu_detach_events\n perf_pmu_unregister\n ..\n\n__pmu_detach_event() sets event->pmu to null. When the perf connection\nfinally is closed, the following stack trace is observed:\n\n Oops: general protection fault, kernel NULL pointer dereference\n ...\n RIP: 0010:_free_event+0x3e/0x370\n ...\n Call Trace:\n ...\n perf_event_release_kernel+0x260/0x2d0\n perf_release+0x12/0x20\n\nA call to mediated_pmu_unaccount_event() inside _free_event() is the root\ncause of this crash. Adding a check inside is_include_guest_event() ensures\nwe don't accidentally access a null pmu ptr. In addition to this, we will\nnow call mediated_pmu_unaccount_event() before clearing the pmu ptr so that\nnr_include_guest_events counts are maintained correctly."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "eff95e170275d9e80b968f335cd03d0ac250d2d1",
              "lessThan": "7fa9a465ae8f07c0e4685db6edb6a6f984dbd784",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "eff95e170275d9e80b968f335cd03d0ac250d2d1",
              "lessThan": "88aed0422f39b22406f35f1e758cea25e7bbcfb5",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/events/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.0",
              "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/7fa9a465ae8f07c0e4685db6edb6a6f984dbd784",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/88aed0422f39b22406f35f1e758cea25e7bbcfb5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}