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| author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-08-22 11:55:07 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-05 12:27:49 +0200 |
| commit | 7ff7d1e7a749843920201489aaed20154eff5a15 (patch) | |
| tree | f6c3de30ac41ab856bdb3b0d7c80531152729bf9 | |
| parent | 9dfd33530c9401ac656a3d3428e977e7cce13b99 (diff) | |
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 1ee6a5527c38..d11de02ecb63 100644 --- a/drivers/media/i2c/ov9650.c +++ b/drivers/media/i2c/ov9650.c @@ -707,6 +707,11 @@ 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); |