[PATCH 4.17 286/336] media: cec: fix smatch error

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans Verkuil <hverkuil@xxxxxxxxx>

[ Upstream commit b66d448487a478c203368f2b72d7d9156a01f6be ]

drivers/media/cec/cec-pin-error-inj.c:231
cec_pin_error_inj_parse_line() error: uninitialized symbol 'pos'.

The tx-add-bytes command didn't check for the presence of an argument, and
also didn't check that it was > 0.

This should fix this error.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/media/cec/cec-pin-error-inj.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/media/cec/cec-pin-error-inj.c
+++ b/drivers/media/cec/cec-pin-error-inj.c
@@ -204,16 +204,18 @@ bool cec_pin_error_inj_parse_line(struct
 		mode_mask = CEC_ERROR_INJ_MODE_MASK << mode_offset;
 		arg_idx = cec_error_inj_cmds[i].arg_idx;
 
-		if (mode_offset == CEC_ERROR_INJ_RX_ARB_LOST_OFFSET ||
-		    mode_offset == CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET)
-			is_bit_pos = false;
-
 		if (mode_offset == CEC_ERROR_INJ_RX_ARB_LOST_OFFSET) {
 			if (has_op)
 				return false;
 			if (!has_pos)
 				pos = 0x0f;
+			is_bit_pos = false;
+		} else if (mode_offset == CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET) {
+			if (!has_pos || !pos)
+				return false;
+			is_bit_pos = false;
 		}
+
 		if (arg_idx >= 0 && is_bit_pos) {
 			if (!has_pos || pos >= 160)
 				return false;