Re: [PATCH] bus: mhi: ep: Fix off by one in mhi_ep_process_cmd_ring()

[Manivannan Sadhasivam <mani@kernel.org>]

On Thu, Jan 26, 2023 at 12:29:10PM +0300, Dan Carpenter wrote:
> The > comparison should be changed to >= to prevent an out of bounds
> access into the mhi_cntrl->mhi_chan[] array.  The mhi_cntrl->mhi_chan[]
> array is allocated in mhi_ep_chan_init() and has mhi_cntrl->max_chan
> elements.
> 
> Fixes: 2527ad44ddb2 ("bus: mhi: ep: Check if the channel is supported by the controller")
> Signed-off-by: Dan Carpenter <error27@gmail.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

Thanks,
Mani

> ---
>  drivers/bus/mhi/ep/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
> index bcaaba97ef63..be2d56e7f392 100644
> --- a/drivers/bus/mhi/ep/main.c
> +++ b/drivers/bus/mhi/ep/main.c
> @@ -125,7 +125,7 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele
>  	ch_id = MHI_TRE_GET_CMD_CHID(el);
>  
>  	/* Check if the channel is supported by the controller */
> -	if ((ch_id > mhi_cntrl->max_chan) || !mhi_cntrl->mhi_chan[ch_id].name) {
> +	if ((ch_id >= mhi_cntrl->max_chan) || !mhi_cntrl->mhi_chan[ch_id].name) {
>  		dev_err(dev, "Channel (%u) not supported!\n", ch_id);
>  		return -ENODEV;
>  	}
> -- 
> 2.35.1
> 

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