From: Ricardo Ribalda Date: Thu, 4 Apr 2024 17:56:18 +0000 (+0000) Subject: media: uvcvideo: Enforce alignment of frame and interval X-Git-Tag: v6.11-rc1~142^2~109^2~9 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8931ef55bd325052ec496f242aea7f6de47dc9c;p=thirdparty%2Fkernel%2Fstable.git media: uvcvideo: Enforce alignment of frame and interval 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: Ricardo Ribalda Reviewed-by: Laurent Pinchart Link: https://lore.kernel.org/r/20240404-uvc-align-v2-1-9e104b0ecfbd@chromium.org Signed-off-by: Laurent Pinchart --- diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index d435b6a6c295d..13c2c11cfdf64 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -687,16 +687,26 @@ 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->formats = format; streaming->nformats = 0;