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Commit d1a4c613 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Greg Kroah-Hartman
Browse files

media: uvcvideo: Enforce alignment of frame and interval 



[ Upstream commit c8931ef55bd325052ec496f242aea7f6de47dc9c ]

Struct uvc_frame and interval (u32*) are packaged together on
streaming->formats on a single contiguous allocation.

Right now they are allocated right after uvc_format, without taking into
consideration their required alignment.

This is working fine because both structures have a field with a
pointer, but it will stop working when the sizeof() of any of those
structs is not a multiple of the sizeof(void*).

Enforce that alignment during the allocation.

Signed-off-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20240404-uvc-align-v2-1-9e104b0ecfbd@chromium.org


Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent d3f56c65

drivers/media/usb/uvc/uvc_driver.c

+14 −4
Original line number Diff line number Diff line
@@ -860,16 +860,26 @@ static int uvc_parse_streaming(struct uvc_device *dev, 
		goto error;

	}



	size = nformats * sizeof(*format) + nframes * sizeof(*frame)

	/*

	 * Allocate memory for the formats, the frames and the intervals,

	 * plus any required padding to guarantee that everything has the

	 * correct alignment.

	 */

	size = nformats * sizeof(*format);

	size = ALIGN(size, __alignof__(*frame)) + nframes * sizeof(*frame);

	size = ALIGN(size, __alignof__(*interval))

	     + nintervals * sizeof(*interval);



	format = kzalloc(size, GFP_KERNEL);

	if (format == NULL) {

	if (!format) {

		ret = -ENOMEM;

		goto error;

	}



	frame = (struct uvc_frame *)&format[nformats];

	interval = (u32 *)&frame[nframes];

	frame = (void *)format + nformats * sizeof(*format);

	frame = PTR_ALIGN(frame, __alignof__(*frame));

	interval = (void *)frame + nframes * sizeof(*frame);

	interval = PTR_ALIGN(interval, __alignof__(*interval));



	streaming->format = format;

	streaming->nformats = nformats;