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Re: [Qemu-devel] [PATCH 1/3] arm: check bit index before use
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 1/3] arm: check bit index before use |
Date: |
Fri, 26 Oct 2018 11:33:03 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 |
On 22/10/2018 14:09, P J P wrote:
> From: Prasad J Pandit <address@hidden>
>
> While performing gpio write via strongarm_gpio_handler_update
> routine, the 'bit' index could access beyond s->handler[28] array.
> Add check to avoid OOB access.
>
> Reported-by: Moguofang <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> hw/arm/strongarm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/arm/strongarm.c b/hw/arm/strongarm.c
> index ec2627374d..3dda75feaf 100644
> --- a/hw/arm/strongarm.c
> +++ b/hw/arm/strongarm.c
> @@ -532,7 +532,9 @@ static void
> strongarm_gpio_handler_update(StrongARMGPIOInfo *s)
>
> for (diff = s->prev_level ^ level; diff; diff ^= 1 << bit) {
> bit = ctz32(diff);
> - qemu_set_irq(s->handler[bit], (level >> bit) & 1);
> + if (bit < sizeof(s->handler) / sizeof(s->handler[0])) {
> + qemu_set_irq(s->handler[bit], (level >> bit) & 1);
> + }
> }
>
> s->prev_level = level;
>
This is correct, but please use ARRAY_SIZE(s->handler).
Paolo