| Message ID | 20210812170043.1046669-1-trix@redhat.com |
|---|---|
| State | Accepted |
| Commit | 48d219f9cc667bc6fbc3e3af0b1bfd75db94fce4 |
| Headers | show |
| Series | media: TDA1997x: handle short reads of hdmi info frame. | expand |
On Thu, Aug 12, 2021 at 10:01 AM <trix@redhat.com> wrote: > > From: Tom Rix <trix@redhat.com> > > 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> > --- > 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 1e2a263be9335..0b995424cb346 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", > -- > 2.26.3 > Reviewed-By: Tim Harvey <tharvey@gateworks.com> Tim
diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c index 1e2a263be9335..0b995424cb346 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",