[PATCH] media: dw2102: Fix size check

From: Ricardo Ribalda
Date: Mon Apr 29 2024 - 11:23:24 EST


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@xxxxxxxxxxxxxxx>
Fixes: 0e148a522b84 ("media: dw2102: Don't translate i2c read into write")
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
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@xxxxxxxxxxxx>