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[media] v4l2-common: fix overflow in v4l_bound_align_image()
Fix clamp_align() used in v4l_bound_align_image() to prevent overflow
when passed large value like UINT32_MAX.
In the current implementation:
clamp_align(UINT32_MAX, 8, 8192, 3)
returns 8, because in line:
x = (x + (1 << (align - 1))) & mask;
x overflows to (-1 + 4) & 0x7 = 3, while expected value is 8192.
v4l_bound_align_image() is heavily used in VIDIOC_S_FMT and
VIDIOC_SUBDEV_S_FMT ioctls handlers, and documentation of the latter
explicitly states that:
"The modified format should be as close as possible to the original
request."
-- http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-subdev-g-fmt.html
Thus one would expect, that passing UINT32_MAX as format width and
height will result in setting maximum possible resolution for the
device. Particularly, when the driver doesn't support
VIDIOC_ENUM_FRAMESIZES ioctl, which is common in the codebase.
Fixes changeset: b0d3159be9
Signed-off-by: Maciej Matraszek <m.matraszek@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
parent
43c3ea312c
commit
3bacc10cd4
1 changed files with 3 additions and 6 deletions
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@ -435,16 +435,13 @@ static unsigned int clamp_align(unsigned int x, unsigned int min,
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/* Bits that must be zero to be aligned */
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unsigned int mask = ~((1 << align) - 1);
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/* Clamp to aligned min and max */
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x = clamp(x, (min + ~mask) & mask, max & mask);
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/* Round to nearest aligned value */
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if (align)
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x = (x + (1 << (align - 1))) & mask;
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/* Clamp to aligned value of min and max */
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if (x < min)
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x = (min + ~mask) & mask;
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else if (x > max)
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x = max & mask;
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return x;
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}
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