From 866d7c1b0a3c70387646c4e455e727a58c5d465a Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Fri, 30 Jun 2017 10:58:28 +0100 Subject: [PATCH] irqchip/gic-v3: Fix out-of-bound access in gic_set_affinity The GICv3 driver doesn't check if the target CPU for gic_set_affinity is valid before going ahead and making the changes. This triggers the following splat with KASAN: [ 141.189434] BUG: KASAN: global-out-of-bounds in gic_set_affinity+0x8c/0x140 [ 141.189704] Read of size 8 at addr ffff200009741d20 by task swapper/1/0 [ 141.189958] [ 141.190158] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc7 [ 141.190458] Hardware name: Foundation-v8A (DT) [ 141.190658] Call trace: [ 141.190908] [] dump_backtrace+0x0/0x328 [ 141.191224] [] show_stack+0x14/0x20 [ 141.191507] [] dump_stack+0xa4/0xc8 [ 141.191858] [] print_address_description+0x13c/0x250 [ 141.192219] [] kasan_report+0x210/0x300 [ 141.192547] [] __asan_load8+0x84/0x98 [ 141.192874] [] gic_set_affinity+0x8c/0x140 [ 141.193158] [] irq_do_set_affinity+0x54/0xb8 [ 141.193473] [] irq_set_affinity_locked+0x64/0xf0 [ 141.193828] [] __irq_set_affinity+0x48/0x78 [ 141.194158] [] arm_perf_starting_cpu+0x104/0x150 [ 141.194513] [] cpuhp_invoke_callback+0x17c/0x1f8 [ 141.194783] [] notify_cpu_starting+0x8c/0xb8 [ 141.195130] [] secondary_start_kernel+0x15c/0x200 [ 141.195390] [<0000000080db81b4>] 0x80db81b4 [ 141.195603] [ 141.195685] The buggy address belongs to the variable: [ 141.196012] __cpu_logical_map+0x200/0x220 [ 141.196176] [ 141.196315] Memory state around the buggy address: [ 141.196586] ffff200009741c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 141.196913] ffff200009741c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 141.197158] >ffff200009741d00: 00 00 00 00 fa fa fa fa 00 00 00 00 00 00 00 00 [ 141.197487] ^ [ 141.197758] ffff200009741d80: 00 00 00 00 00 00 00 00 fa fa fa fa 00 00 00 00 [ 141.198060] ffff200009741e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 141.198358] ================================================================== [ 141.198609] Disabling lock debugging due to kernel taint [ 141.198961] CPU1: Booted secondary processor [410fd051] This patch adds the check to make sure the cpu is valid. Fixes: commit 021f653791ad17e03f98 ("irqchip: gic-v3: Initial support for GICv3") Cc: stable@vger.kernel.org Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic-v3.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index c132f29322cc..dbffb7ab6203 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -645,6 +645,9 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, int enabled; u64 val; + if (cpu >= nr_cpu_ids) + return -EINVAL; + if (gic_irq_in_rdist(d)) return -EINVAL; -- 2.20.1