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From:   Vikash Garodia <quic_vgarodia@quicinc.com>
To:     <stanimir.k.varbanov@gmail.com>, <bryan.odonoghue@linaro.org>,
        <agross@kernel.org>, <andersson@kernel.org>,
        <konrad.dybcio@linaro.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>,
        Vikash Garodia <quic_vgarodia@quicinc.com>
Subject: [PATCH v2 1/4] venus: hfi: add checks to perform sanity on queue pointers
Date:   Thu, 10 Aug 2023 07:55:01 +0530
Message-ID: <1691634304-2158-2-git-send-email-quic_vgarodia@quicinc.com>
In-Reply-To: <1691634304-2158-1-git-send-email-quic_vgarodia@quicinc.com>
References: <1691634304-2158-1-git-send-email-quic_vgarodia@quicinc.com>
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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 | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
index f0b4638..4ddabb1 100644
--- a/drivers/media/platform/qcom/venus/hfi_venus.c
+++ b/drivers/media/platform/qcom/venus/hfi_venus.c
@@ -206,6 +206,11 @@ 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 - sizeof(*wr_ptr)))
+		return -EINVAL;
+
 	if (new_wr_idx < qsize) {
 		memcpy(wr_ptr, packet, dwords << 2);
 	} else {
@@ -273,6 +278,11 @@ static int venus_read_queue(struct venus_hfi_device *hdev,
 	}
 
 	rd_ptr = (u32 *)(queue->qmem.kva + (rd_idx << 2));
+
+	if (rd_ptr < (u32 *)queue->qmem.kva ||
+	    rd_ptr > (u32 *)(queue->qmem.kva + queue->qmem.size - sizeof(*rd_ptr)))
+		return -EINVAL;
+
 	dwords = *rd_ptr >> 2;
 	if (!dwords)
 		return -EINVAL;
-- 
2.7.4