diff options
| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-08-22 17:55:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 13:47:56 +0300 |
| commit | d4fa9bf6c2c21e8757d0eb8458786e47b4522f7e (patch) | |
| tree | 2b7ad23db2b0402a5832c49ca82da5d839f342fe | |
| parent | d792650edbf054cc528dfb8756405cfc978c7996 (diff) | |
| download | linux-d4fa9bf6c2c21e8757d0eb8458786e47b4522f7e.tar.xz | |
media: ov9650: add a sanity check
[ Upstream commit 093347abc7a4e0490e3c962ecbde2dc272a8f708 ]
As pointed by cppcheck:
[drivers/media/i2c/ov9650.c:706]: (error) Shifting by a negative value is undefined behaviour
[drivers/media/i2c/ov9650.c:707]: (error) Shifting by a negative value is undefined behaviour
[drivers/media/i2c/ov9650.c:721]: (error) Shifting by a negative value is undefined behaviour
Prevent mangling with gains with invalid values.
As pointed by Sylvester, this should never happen in practice,
as min value of V4L2_CID_GAIN control is 16 (gain is always >= 16
and m is always >= 0), but it is too hard for a static analyzer
to get this, as the logic with validates control min/max is
elsewhere inside V4L2 core.
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/media/i2c/ov9650.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/media/i2c/ov9650.c b/drivers/media/i2c/ov9650.c index 6ffb460e8589..565903c3172d 100644 --- a/drivers/media/i2c/ov9650.c +++ b/drivers/media/i2c/ov9650.c @@ -710,6 +710,11 @@ static int ov965x_set_gain(struct ov965x *ov965x, int auto_gain) for (m = 6; m >= 0; m--) if (gain >= (1 << m) * 16) break; + + /* Sanity check: don't adjust the gain with a negative value */ + if (m < 0) + return -EINVAL; + rgain = (gain - ((1 << m) * 16)) / (1 << m); rgain |= (((1 << m) - 1) << 4); |