{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/perf/vpa-pmu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "70ea7c5189197c6f5acdcfd8a2651be2c41e2faa",
              "status": "affected",
              "version": "176cda0619b6c17a553625f6e2fcbc3981ad667d",
              "versionType": "git"
            },
            {
              "lessThan": "6cf045b51e2c5721db7e55305f09ee32741e00f9",
              "status": "affected",
              "version": "176cda0619b6c17a553625f6e2fcbc3981ad667d",
              "versionType": "git"
            },
            {
              "lessThan": "ff99d5b6a246715f2257123cdf6c4a29cb33aa78",
              "status": "affected",
              "version": "176cda0619b6c17a553625f6e2fcbc3981ad667d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/powerpc/perf/vpa-pmu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.14.*",
              "status": "unaffected",
              "version": "6.14.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.11",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14.2",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.15",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/perf: Fix ref-counting on the PMU \u0027vpa_pmu\u0027\n\nCommit 176cda0619b6 (\"powerpc/perf: Add perf interface to expose vpa\ncounters\") introduced \u0027vpa_pmu\u0027 to expose Book3s-HV nested APIv2 provided\nL1\u003c-\u003eL2 context switch latency counters to L1 user-space via\nperf-events. However the newly introduced PMU named \u0027vpa_pmu\u0027 doesn\u0027t\nassign ownership of the PMU to the module \u0027vpa_pmu\u0027. Consequently the\nmodule \u0027vpa_pmu\u0027 can be unloaded while one of the perf-events are still\nactive, which can lead to kernel oops and panic of the form below on a\nPseries-LPAR:\n\nBUG: Kernel NULL pointer dereference on read at 0x00000058\n\u003csnip\u003e\n NIP [c000000000506cb8] event_sched_out+0x40/0x258\n LR [c00000000050e8a4] __perf_remove_from_context+0x7c/0x2b0\n Call Trace:\n [c00000025fc3fc30] [c00000025f8457a8] 0xc00000025f8457a8 (unreliable)\n [c00000025fc3fc80] [fffffffffffffee0] 0xfffffffffffffee0\n [c00000025fc3fcd0] [c000000000501e70] event_function+0xa8/0x120\n\u003csnip\u003e\n Kernel panic - not syncing: Aiee, killing interrupt handler!\n\nFix this by adding the module ownership to \u0027vpa_pmu\u0027 so that the module\n\u0027vpa_pmu\u0027 is ref-counted and prevented from being unloaded when perf-events\nare initialized."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerability is reached entirely through local syscalls \u2014 `perf_event_open(2)` to bind an event to the `vpa_pmu` PMU and `delete_module(2)` to unload the module. There is no network or remote-peer input path to this powerpc perf driver.\nAC:L - The attacker deterministically sets up the condition by holding a `vpa_pmu` perf event open indefinitely; there is no race to win and no memory layout beyond the attacker\u0027s influence, so any subsequent module unload reliably hits a live dangling event.\nPR:L - The missing module reference is taken (or rather, not taken) on behalf of an ordinary local user calling `perf_event_open` \u2014 no capability is checked in `vpa_pmu_event_init()`, and the `perf_allow_kernel()` gate is open to unprivileged users whenever `kernel.perf_event_paranoid \u003c= 1`, a routine setting on the profiling/KVM-on-PowerVM hosts where this PMU is deployed.\nUI:R - Triggering the use-after-free requires the module to actually be unloaded, and `delete_module(2)` demands `CAP_SYS_MODULE` in the initial user namespace, which the low-privileged attacker cannot obtain via user namespaces \u2014 so an administrator\u0027s `rmmod vpa_pmu` (routine after a perf measurement session) is the required second-party action.\nS:U - The freed `struct pmu` and module text belong to the same kernel that the attacker\u0027s process already runs under, so impact stays within one security authority. Although `vpa_pmu` relates to KVM-on-PowerVM, the driver only runs on the L1 LPAR and the corruption never crosses the guest/host boundary.\nC:H - This is a use-after-free of a `struct pmu` living in vfree\u0027d module memory, including a stale `pmu-\u003epmu_disable_count` percpu pointer that is read on every event schedule; reclaiming that memory (e.g. by loading another module) turns the dangling reads into a kernel memory disclosure primitive.\nI:H - The dangling `event-\u003epmu` still carries `-\u003eadd`, `-\u003edel` and `-\u003eread` function pointers into freed module text, so the perf core makes indirect calls through attacker-influenceable reclaimed memory \u2014 a control-flow hijack primitive, not merely stale data.\nA:H - The commit documents the concrete outcome: a NULL pointer dereference in `event_sched_out()` reached from `__perf_remove_from_context()`, escalating to `Kernel panic - not syncing: Aiee, killing interrupt handler!` \u2014 a full system crash."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:56:45.289Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/70ea7c5189197c6f5acdcfd8a2651be2c41e2faa"
        },
        {
          "url": "https://git.kernel.org/stable/c/6cf045b51e2c5721db7e55305f09ee32741e00f9"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff99d5b6a246715f2257123cdf6c4a29cb33aa78"
        }
      ],
      "title": "powerpc/perf: Fix ref-counting on the PMU \u0027vpa_pmu\u0027",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-22094",
    "datePublished": "2025-04-16T14:12:45.512Z",
    "dateReserved": "2024-12-29T08:45:45.818Z",
    "dateUpdated": "2026-08-05T11:56:45.289Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}