{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Fix event leak upon exit\n\nWhen a task is scheduled out, pending sigtrap deliveries are deferred\nto the target task upon resume to userspace via task_work.\n\nHowever failures while adding an event's callback to the task_work\nengine are ignored. And since the last call for events exit happen\nafter task work is eventually closed, there is a small window during\nwhich pending sigtrap can be queued though ignored, leaking the event\nrefcount addition such as in the following scenario:\n\n    TASK A\n    -----\n\n    do_exit()\n       exit_task_work(tsk);\n\n       <IRQ>\n       perf_event_overflow()\n          event->pending_sigtrap = pending_id;\n          irq_work_queue(&event->pending_irq);\n       </IRQ>\n    =========> PREEMPTION: TASK A -> TASK B\n       event_sched_out()\n          event->pending_sigtrap = 0;\n          atomic_long_inc_not_zero(&event->refcount)\n          // FAILS: task work has exited\n          task_work_add(&event->pending_task)\n       [...]\n       <IRQ WORK>\n       perf_pending_irq()\n          // early return: event->oncpu = -1\n       </IRQ WORK>\n       [...]\n    =========> TASK B -> TASK A\n       perf_event_exit_task(tsk)\n          perf_event_exit_event()\n             free_event()\n                WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1)\n                // leak event due to unexpected refcount == 2\n\nAs a result the event is never released while the task exits.\n\nFix this with appropriate task_work_add()'s error handling."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "kernel/events/core.c"
               ],
               "versions": [
                  {
                     "version": "8bffa95ac19f",
                     "lessThan": "67fad724f1b5",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "517e6a301f34",
                     "lessThan": "70882d7fa74f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "517e6a301f34",
                     "lessThan": "05d3fd599594",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "517e6a301f34",
                     "lessThan": "3d7a63352a93",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "517e6a301f34",
                     "lessThan": "2fd5ad3f310d",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "kernel/events/core.c"
               ],
               "versions": [
                  {
                     "version": "6.1",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "6.1",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.165",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.103",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.44",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10.3",
                     "lessThanOrEqual": "6.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.11",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/67fad724f1b568b356c1065d50df46e6b30eb2f7"
            },
            {
               "url": "https://git.kernel.org/stable/c/70882d7fa74f0731492a0d493e8515a4f7131831"
            },
            {
               "url": "https://git.kernel.org/stable/c/05d3fd599594abf79aad4484bccb2b26e1cb0b51"
            },
            {
               "url": "https://git.kernel.org/stable/c/3d7a63352a93bdb8a1cdf29606bf617d3ac1c22a"
            },
            {
               "url": "https://git.kernel.org/stable/c/2fd5ad3f310de22836cdacae919dd99d758a1f1b"
            }
         ],
         "title": "perf: Fix event leak upon exit",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-43870",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}