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CVE-2026-23435: Linux

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CVSS

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Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

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    Описание

    Оригинално описание

    In the Linux kernel, the following vulnerability has been resolved: perf/x86: Move event pointer setup earlier in x86_pmu_enable() A production AMD EPYC system crashed with a NULL pointer dereference in the PMU NMI handler: BUG: kernel NULL pointer dereference, address: 0000000000000198 RIP: x86_perf_event_update+0xc/0xa0 Call Trace: <NMI> amd_pmu_v2_handle_irq+0x1a6/0x390 perf_event_nmi_handler+0x24/0x40 The faulting instruction is `cmpq $0x0, 0x198(%rdi)` with RDI=0, corresponding to the `if (unlikely(!hwc->event_base))` check in x86_perf_event_update() where hwc = &event->hw and event is NULL. drgn inspection of the vmcore on CPU 106 showed a mismatch between cpuc->active_mask and cpuc->events[]: active_mask: 0x1e (bits 1, 2, 3, 4) events[1]: 0xff1100136cbd4f38 (valid) events[2]: 0x0 (NULL, but active_mask bit 2 set) events[3]: 0xff1100076fd2cf38 (valid) events[4]: 0xff1100079e990a90 (valid) The event that should occupy events[2] was found in event_list[2] with hw.idx=2 and hw.state=0x0, confirming x86_pmu_start() had run (which clears hw.state and sets active_mask) but events[2] was never populated. Another event (event_list[0]) had hw.state=0x7 (STOPPED|UPTODATE|ARCH), showing it was stopped when the PMU rescheduled events, confirming the throttle-then-reschedule sequence occurred. The root cause is commit 7e772a93eb61 ("perf/x86: Fix NULL event access and potential PEBS record loss") which moved the cpuc->events[idx] assignment out of x86_pmu_start() and into step 2 of x86_pmu_enable(), after the PERF_HES_ARCH check. This broke any path that calls pmu->start() without going through x86_pmu_enable() -- specifically the unthrottle path: perf_adjust_freq_unthr_events() -> perf_event_unthrottle_group() -> perf_event_unthrottle() -> event->pmu->start(event, 0) -> x86_pmu_start() // sets active_mask but not events[] The race sequence is: 1. A group of perf events over

    Засегнати продукти

    • Linux Linux: 6b089028bff1f2ff9e0c62b8f1faca1a620e5d6e преди 886fa869153917d902784098922defa20c3a2fe5; 7e772a93eb61cb6265bdd1c5bde17d0f2718b452 преди c1dd1e2b722d3f1f2e4977dad8d1be78fdfb30cb; 7e772a93eb61cb6265bdd1c5bde17d0f2718b452 преди 8d5fae6011260de209aaf231120e8146b14bc8e0; cf69b99805c263117305ac6dffbc85aaf9259d32; 6.18.2 преди 6.18.20; 6.17.13 преди 6.18
    • Linux Linux: 6.19; преди 6.19; 6.18.20 до 6.18.*; 6.19.10 до 6.19.*; от 7.0 нататък

    История

    • 3 април 2026 Публикувано

    Други уязвимости в Linux Linux

    Първоизточници

    CVE-2026-23435: Linux | freedomonline.bg