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Message-ID: <6692f826-c2ca-3f8e-c6e5-d02a99150095@quicinc.com>
Date:   Fri, 28 Jul 2023 13:26:58 +0530
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Subject: Re: [PATCH 1/4] venus: hfi: add checks to perform sanity on queue
 pointers
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To:     Konrad Dybcio <konrad.dybcio@linaro.org>,
        <stanimir.k.varbanov@gmail.com>, <bryan.odonoghue@linaro.org>,
        <agross@kernel.org>, <andersson@kernel.org>, <mchehab@kernel.org>,
        <hans.verkuil@cisco.com>, <tfiga@chromium.org>
CC:     <linux-media@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>
References: <1690432469-14803-1-git-send-email-quic_vgarodia@quicinc.com>
 <1690432469-14803-2-git-send-email-quic_vgarodia@quicinc.com>
 <df947545-23ef-2ee9-72cc-8e54bbe46be1@linaro.org>
From:   Vikash Garodia <quic_vgarodia@quicinc.com>
In-Reply-To: <df947545-23ef-2ee9-72cc-8e54bbe46be1@linaro.org>
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On 7/27/2023 10:38 PM, Konrad Dybcio wrote:
> On 27.07.2023 06:34, Vikash Garodia wrote:
>> Read and write pointers are used to track the packet index in the memory
>> shared between video driver and firmware. There is a possibility of OOB
>> access if the read or write pointer goes beyond the queue memory size.
>> Add checks for the read and write pointer to avoid OOB access.
>>
>> Cc: stable@vger.kernel.org
>> Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
>> Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
>> ---
>>  drivers/media/platform/qcom/venus/hfi_venus.c | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
>> index f0b4638..dc228c4 100644
>> --- a/drivers/media/platform/qcom/venus/hfi_venus.c
>> +++ b/drivers/media/platform/qcom/venus/hfi_venus.c
>> @@ -206,6 +206,10 @@ static int venus_write_queue(struct venus_hfi_device *hdev,
>>  
>>  	new_wr_idx = wr_idx + dwords;
>>  	wr_ptr = (u32 *)(queue->qmem.kva + (wr_idx << 2));
>> +
>> +	if (wr_ptr < (u32 *)queue->qmem.kva || wr_ptr > (u32 *)(queue->qmem.kva + queue->qmem.size))
> Shouldn't the cases on the right side of the OR operator include a
> "- 1"?

I see your point here. Possibly subtracting with sizeof(*wr_ptr) instead of "1"
would be appropriate. Similarly for read queue handling.

- Vikash

> Konrad