From ab8da93dc06d82f464c47ab30e6c75190702f369 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Sun, 20 Feb 2022 11:38:15 +0100 Subject: [PATCH] clocksource/drivers/exynos_mct: Handle DTS with higher number of interrupts The driver statically defines maximum number of interrupts it can handle, however it does not respect that limit when configuring them. When provided with a DTS with more interrupts than assumed, the driver will overwrite static array mct_irqs leading to silent memory corruption. Validate the interrupts coming from DTS to avoid this. This does not change the fact that such DTS might not boot at all, because it is simply incompatible, however at least some warning will be printed. Fixes: 36ba5d527e95 ("ARM: EXYNOS: add device tree support for MCT controller driver") Signed-off-by: Krzysztof Kozlowski Reviewed-by: Alim Akhtar Link: https://lore.kernel.org/r/20220220103815.135380-1-krzysztof.kozlowski@canonical.com Signed-off-by: Daniel Lezcano --- drivers/clocksource/exynos_mct.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index 6db3d551..03782b3 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -541,6 +541,11 @@ static int __init exynos4_timer_interrupts(struct device_node *np, * irqs are specified. */ nr_irqs = of_irq_count(np); + if (nr_irqs > ARRAY_SIZE(mct_irqs)) { + pr_err("exynos-mct: too many (%d) interrupts configured in DT\n", + nr_irqs); + nr_irqs = ARRAY_SIZE(mct_irqs); + } for (i = MCT_L0_IRQ; i < nr_irqs; i++) mct_irqs[i] = irq_of_parse_and_map(np, i); @@ -553,11 +558,14 @@ static int __init exynos4_timer_interrupts(struct device_node *np, mct_irqs[MCT_L0_IRQ], err); } else { for_each_possible_cpu(cpu) { - int mct_irq = mct_irqs[MCT_L0_IRQ + cpu]; + int mct_irq; struct mct_clock_event_device *pcpu_mevt = per_cpu_ptr(&percpu_mct_tick, cpu); pcpu_mevt->evt.irq = -1; + if (MCT_L0_IRQ + cpu >= ARRAY_SIZE(mct_irqs)) + break; + mct_irq = mct_irqs[MCT_L0_IRQ + cpu]; irq_set_status_flags(mct_irq, IRQ_NOAUTOEN); if (request_irq(mct_irq, -- 2.7.4