CVE-2023-53583

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> perf: RISC-V: Remove PERF_HES_STOPPED flag checking in riscv_pmu_start()<br /> <br /> Since commit 096b52fd2bb4 ("perf: RISC-V: throttle perf events") the<br /> perf_sample_event_took() function was added to report time spent in<br /> overflow interrupts. If the interrupt takes too long, the perf framework<br /> will lower the sysctl_perf_event_sample_rate and max_samples_per_tick.<br /> When hwc-&gt;interrupts is larger than max_samples_per_tick, the<br /> hwc-&gt;interrupts will be set to MAX_INTERRUPTS, and events will be<br /> throttled within the __perf_event_account_interrupt() function.<br /> <br /> However, the RISC-V PMU driver doesn&amp;#39;t call riscv_pmu_stop() to update the<br /> PERF_HES_STOPPED flag after perf_event_overflow() in pmu_sbi_ovf_handler()<br /> function to avoid throttling. When the perf framework unthrottled the event<br /> in the timer interrupt handler, it triggers riscv_pmu_start() function<br /> and causes a WARN_ON_ONCE() warning, as shown below:<br /> <br /> ------------[ cut here ]------------<br /> WARNING: CPU: 0 PID: 240 at drivers/perf/riscv_pmu.c:184 riscv_pmu_start+0x7c/0x8e<br /> Modules linked in:<br /> CPU: 0 PID: 240 Comm: ls Not tainted 6.4-rc4-g19d0788e9ef2 #1<br /> Hardware name: SiFive (DT)<br /> epc : riscv_pmu_start+0x7c/0x8e<br /> ra : riscv_pmu_start+0x28/0x8e<br /> epc : ffffffff80aef864 ra : ffffffff80aef810 sp : ffff8f80004db6f0<br /> gp : ffffffff81c83750 tp : ffffaf80069f9bc0 t0 : ffff8f80004db6c0<br /> t1 : 0000000000000000 t2 : 000000000000001f s0 : ffff8f80004db720<br /> s1 : ffffaf8008ca1068 a0 : 0000ffffffffffff a1 : 0000000000000000<br /> a2 : 0000000000000001 a3 : 0000000000000870 a4 : 0000000000000000<br /> a5 : 0000000000000000 a6 : 0000000000000840 a7 : 0000000000000030<br /> s2 : 0000000000000000 s3 : ffffaf8005165800 s4 : ffffaf800424da00<br /> s5 : ffffffffffffffff s6 : ffffffff81cc7590 s7 : 0000000000000000<br /> s8 : 0000000000000006 s9 : 0000000000000001 s10: ffffaf807efbc340<br /> s11: ffffaf807efbbf00 t3 : ffffaf8006a16028 t4 : 00000000dbfbb796<br /> t5 : 0000000700000000 t6 : ffffaf8005269870<br /> status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003<br /> [] riscv_pmu_start+0x7c/0x8e<br /> [] perf_adjust_freq_unthr_context+0x15e/0x174<br /> [] perf_event_task_tick+0x88/0x9c<br /> [] scheduler_tick+0xfe/0x27c<br /> [] update_process_times+0x9a/0xba<br /> [] tick_sched_handle+0x32/0x66<br /> [] tick_sched_timer+0x64/0xb0<br /> [] __hrtimer_run_queues+0x156/0x2f4<br /> [] hrtimer_interrupt+0xe2/0x1fe<br /> [] riscv_timer_interrupt+0x38/0x42<br /> [] handle_percpu_devid_irq+0x90/0x1d2<br /> [] generic_handle_domain_irq+0x28/0x36<br /> <br /> After referring other PMU drivers like Arm, Loongarch, Csky, and Mips,<br /> they don&amp;#39;t call *_pmu_stop() to update with PERF_HES_STOPPED flag<br /> after perf_event_overflow() function nor do they add PERF_HES_STOPPED<br /> flag checking in *_pmu_start() which don&amp;#39;t cause this warning.<br /> <br /> Thus, it&amp;#39;s recommended to remove this unnecessary check in<br /> riscv_pmu_start() function to prevent this warning.