From: Tom Rix trix@redhat.com
[ Upstream commit 48d219f9cc667bc6fbc3e3af0b1bfd75db94fce4 ]
Static analysis reports this representative problem
tda1997x.c:1939: warning: 7th function call argument is an uninitialized value
The 7th argument is buffer[0], which is set in the earlier call to io_readn(). When io_readn() call to io_read() fails with the first read, buffer[0] is not set and 0 is returned and stored in len.
The later call to hdmi_infoframe_unpack()'s size parameter is the static size of buffer, always 40, so a short read is not caught in hdmi_infoframe_unpacks()'s checking. The variable len should be used instead.
Zero initialize buffer to 0 so it is in a known start state.
Fixes: 9ac0038db9a7 ("media: i2c: Add TDA1997x HDMI receiver driver") Signed-off-by: Tom Rix trix@redhat.com Reviewed-by: Tim Harvey tharvey@gateworks.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/i2c/tda1997x.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c index 6070aaf0b32ea..4dafa9f1cf522 100644 --- a/drivers/media/i2c/tda1997x.c +++ b/drivers/media/i2c/tda1997x.c @@ -1248,13 +1248,13 @@ tda1997x_parse_infoframe(struct tda1997x_state *state, u16 addr) { struct v4l2_subdev *sd = &state->sd; union hdmi_infoframe frame; - u8 buffer[40]; + u8 buffer[40] = { 0 }; u8 reg; int len, err;
/* read data */ len = io_readn(sd, addr, sizeof(buffer), buffer); - err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)); + err = hdmi_infoframe_unpack(&frame, buffer, len); if (err) { v4l_err(state->client, "failed parsing %d byte infoframe: 0x%04x/0x%02x\n", @@ -1928,13 +1928,13 @@ static int tda1997x_log_infoframe(struct v4l2_subdev *sd, int addr) { struct tda1997x_state *state = to_state(sd); union hdmi_infoframe frame; - u8 buffer[40]; + u8 buffer[40] = { 0 }; int len, err;
/* read data */ len = io_readn(sd, addr, sizeof(buffer), buffer); v4l2_dbg(1, debug, sd, "infoframe: addr=%d len=%d\n", addr, len); - err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)); + err = hdmi_infoframe_unpack(&frame, buffer, len); if (err) { v4l_err(state->client, "failed parsing %d byte infoframe: 0x%04x/0x%02x\n",