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| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-08-22 11:55:07 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-08-26 14:05:09 -0300 |
| commit | 093347abc7a4e0490e3c962ecbde2dc272a8f708 (patch) | |
| tree | 3903cdeeea2628b0e151a2fbda2175f25ef9db01 /drivers/media | |
| parent | 31b8b0bd6e55c3ea5a08bb8141fa5d3c90600e3b (diff) | |
| download | linux-093347abc7a4e0490e3c962ecbde2dc272a8f708.tar.bz2 | |
media: ov9650: add a sanity check
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>
Diffstat (limited to 'drivers/media')
| -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 8b56011446a9..4fe68aa55789 100644 --- a/drivers/media/i2c/ov9650.c +++ b/drivers/media/i2c/ov9650.c @@ -703,6 +703,11 @@ 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); |