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From: Ricardo Ribalda <ribalda@chromium.org>
Date: Mon, 29 Apr 2024 15:20:18 +0000
Subject: [PATCH] media: dw2102: Fix size check
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Message-Id: <20240429-dw2102-v1-1-a5d81dfc1453@chromium.org>
To: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>, linux-media@vger.kernel.org, 
 linux-kernel@vger.kernel.org, stable@vger.kernel.org, 
 Ricardo Ribalda <ribalda@chromium.org>

The data is going to be copied at state->data[4], not at state->data[1],
fix the check to avoid stack overruns.

Found with smatch:
drivers/media/usb/dvb-usb/dw2102.c:802 su3000_i2c_transfer() error: __builtin_memcpy() '&state->data[4]' too small (64 vs 67)
drivers/media/usb/dvb-usb/dw2102.c:802 su3000_i2c_transfer() error: __builtin_memcpy() '&state->data[4]' too small (64 vs 67)

Cc:  <stable@vger.kernel.org>
Fixes: 0e148a522b84 ("media: dw2102: Don't translate i2c read into write")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
This time it could be relevant though.
---
 drivers/media/usb/dvb-usb/dw2102.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb/dw2102.c
index 03b411ad64bb..79e2ccf974c9 100644
--- a/drivers/media/usb/dvb-usb/dw2102.c
+++ b/drivers/media/usb/dvb-usb/dw2102.c
@@ -789,7 +789,7 @@ static int su3000_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[],
 
 			if (msg[j].flags & I2C_M_RD) {
 				/* single read */
-				if (1 + msg[j].len > sizeof(state->data)) {
+				if (4 + msg[j].len > sizeof(state->data)) {
 					warn("i2c rd: len=%d is too big!\n", msg[j].len);
 					num = -EOPNOTSUPP;
 					break;

---
base-commit: cefc10d0d9164eb2f62e789b69dc658dc851eb58
change-id: 20240429-dw2102-ed3d128a1582

Best regards,
-- 
Ricardo Ribalda <ribalda@chromium.org>