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authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-08-22 17:55:07 +0300
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-08-26 20:05:09 +0300
commit093347abc7a4e0490e3c962ecbde2dc272a8f708 (patch)
tree3903cdeeea2628b0e151a2fbda2175f25ef9db01 /drivers/media
parent31b8b0bd6e55c3ea5a08bb8141fa5d3c90600e3b (diff)
downloadlinux-093347abc7a4e0490e3c962ecbde2dc272a8f708.tar.xz
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.c5
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);