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From: Ricardo Ribalda <ribalda@chromium.org>
Date: Fri, 19 Apr 2024 09:48:11 +0000
Subject: [PATCH v2 25/26] media: dvb-frontends: tda10048: Fix integer
 overflow
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To: Martin Tuma <martin.tuma@digiteqautomotive.com>, 
 Mauro Carvalho Chehab <mchehab@kernel.org>, 
 Laurent Pinchart <laurent.pinchart@ideasonboard.com>, 
 Hugues Fruchet <hugues.fruchet@foss.st.com>, 
 Alain Volmat <alain.volmat@foss.st.com>, 
 Maxime Coquelin <mcoquelin.stm32@gmail.com>, 
 Alexandre Torgue <alexandre.torgue@foss.st.com>, 
 Paul Kocialkowski <paul.kocialkowski@bootlin.com>, 
 Greg Kroah-Hartman <gregkh@linuxfoundation.org>, 
 Chen-Yu Tsai <wens@csie.org>, Jernej Skrabec <jernej.skrabec@gmail.com>, 
 Samuel Holland <samuel@sholland.org>, 
 Sakari Ailus <sakari.ailus@linux.intel.com>, 
 Thierry Reding <thierry.reding@gmail.com>, 
 Jonathan Hunter <jonathanh@nvidia.com>, 
 Sowjanya Komatineni <skomatineni@nvidia.com>, 
 Luca Ceresoli <luca.ceresoli@bootlin.com>, 
 Matthias Brugger <matthias.bgg@gmail.com>, 
 AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>, 
 Hans Verkuil <hverkuil@xs4all.nl>, Sergey Kozlov <serjk@netup.ru>, 
 Abylay Ospan <aospan@netup.ru>, 
 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>, 
 Dmitry Osipenko <digetx@gmail.com>, 
 Benjamin Mugnier <benjamin.mugnier@foss.st.com>, 
 Sylvain Petinot <sylvain.petinot@foss.st.com>, 
 Stanimir Varbanov <stanimir.k.varbanov@gmail.com>, 
 Vikash Garodia <quic_vgarodia@quicinc.com>, 
 Bryan O'Donoghue <bryan.odonoghue@linaro.org>, 
 Bjorn Andersson <andersson@kernel.org>, 
 Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-stm32@st-md-mailman.stormreply.com, 
 linux-arm-kernel@lists.infradead.org, linux-staging@lists.linux.dev, 
 linux-sunxi@lists.linux.dev, linux-tegra@vger.kernel.org, 
 linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, 
 Ricardo Ribalda <ribalda@chromium.org>, 
 Dan Carpenter <dan.carpenter@linaro.org>

state->xtal_hz can be up to 16M, so it can overflow a 32 bit integer
when multiplied by pll_mfactor.

Create a new 64 bit variable to hold the calculations.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/dvb-frontends/tda10048.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/dvb-frontends/tda10048.c b/drivers/media/dvb-frontends/tda10048.c
index 5d5e4e9e4422..3e725cdcc66b 100644
--- a/drivers/media/dvb-frontends/tda10048.c
+++ b/drivers/media/dvb-frontends/tda10048.c
@@ -410,6 +410,7 @@ static int tda10048_set_if(struct dvb_frontend *fe, u32 bw)
 	struct tda10048_config *config = &state->config;
 	int i;
 	u32 if_freq_khz;
+	u64 sample_freq;
 
 	dprintk(1, "%s(bw = %d)\n", __func__, bw);
 
@@ -451,9 +452,11 @@ static int tda10048_set_if(struct dvb_frontend *fe, u32 bw)
 	dprintk(1, "- pll_pfactor = %d\n", state->pll_pfactor);
 
 	/* Calculate the sample frequency */
-	state->sample_freq = state->xtal_hz * (state->pll_mfactor + 45);
-	state->sample_freq /= (state->pll_nfactor + 1);
-	state->sample_freq /= (state->pll_pfactor + 4);
+	sample_freq = state->xtal_hz;
+	sample_freq *= state->pll_mfactor + 45;
+	do_div(sample_freq, state->pll_nfactor + 1);
+	do_div(sample_freq, state->pll_pfactor + 4);
+	state->sample_freq = sample_freq;
 	dprintk(1, "- sample_freq = %d\n", state->sample_freq);
 
 	/* Update the I/F */

-- 
2.44.0.769.g3c40516874-goog