v4l2-common: fix overflow in v4l_bound_align_image()
commit 3bacc10c upstream. 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: b0d3159bSigned-off-by: Maciej Matraszek <m.matraszek@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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