From: Mauro Carvalho Chehab Date: Thu, 22 Aug 2019 14:55:07 +0000 (-0300) Subject: media: ov9650: add a sanity check X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d4fa9bf6c2c21e8757d0eb8458786e47b4522f7e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- 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);