releases/5.4.280/media-dvb-frontends-tda10048-fix-integer-overflow.patch

From 1bc14f35dd2ddd636f2fb458f20787595c641df3 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 29 Apr 2024 16:05:04 +0100
Subject: media: dvb-frontends: tda10048: Fix integer overflow

From: Ricardo Ribalda <ribalda@chromium.org>

[ Upstream commit 1aa1329a67cc214c3b7bd2a14d1301a795760b07 ]

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.

Link: https://lore.kernel.org/linux-media/20240429-fix-cocci-v3-25-3c4865f5a4b0@chromium.org
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.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 f1d5e77d5dcce..db829754f1359 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 */
-- 
2.43.0