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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 4/4] venus: hfi_parser: Add check to keep the number of codecs within range
Date:   Thu, 10 Aug 2023 07:55:04 +0530
Message-ID: <1691634304-2158-5-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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Supported codec bitmask is populated from the payload from venus firmware.
There is a possible case when all the bits in the codec bitmask is set. In
such case, core cap for decoder is filled  and MAX_CODEC_NUM is utilized.
Now while filling the caps for encoder, it can lead to access the caps
array beyong 32 index. Hence leading to OOB write.
The fix counts the supported encoder and decoder. If the count is more than
max, then it skips accessing the caps.

Cc: stable@vger.kernel.org
Fixes: 1a73374a04e5 ("media: venus: hfi_parser: add common capability parser")
Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
---
 drivers/media/platform/qcom/venus/hfi_parser.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/media/platform/qcom/venus/hfi_parser.c b/drivers/media/platform/qcom/venus/hfi_parser.c
index 9d6ba22..c438395 100644
--- a/drivers/media/platform/qcom/venus/hfi_parser.c
+++ b/drivers/media/platform/qcom/venus/hfi_parser.c
@@ -19,6 +19,9 @@ static void init_codecs(struct venus_core *core)
 	struct hfi_plat_caps *caps = core->caps, *cap;
 	unsigned long bit;
 
+	if (hweight_long(core->dec_codecs) + hweight_long(core->enc_codecs) > MAX_CODEC_NUM)
+		return;
+
 	for_each_set_bit(bit, &core->dec_codecs, MAX_CODEC_NUM) {
 		cap = &caps[core->codecs_count++];
 		cap->codec = BIT(bit);
-- 
2.7.4