{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-43870",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "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."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "8bffa95ac19f",
                                            "version_value": "67fad724f1b5"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "517e6a301f34",
                                            "version_value": "70882d7fa74f"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.1",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.1",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "5.15.165",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.1.103",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.6.44",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.10.3",
                                                        "lessThanOrEqual": "6.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.11",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
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                                                "defaultStatus": "affected"
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    "references": {
        "reference_data": [
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                "url": "https://git.kernel.org/stable/c/67fad724f1b568b356c1065d50df46e6b30eb2f7",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/67fad724f1b568b356c1065d50df46e6b30eb2f7"
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                "name": "https://git.kernel.org/stable/c/70882d7fa74f0731492a0d493e8515a4f7131831"
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                "name": "https://git.kernel.org/stable/c/3d7a63352a93bdb8a1cdf29606bf617d3ac1c22a"
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