4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> [ 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: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240404-uvc-align-v2-1-9e104b0ecfbd@xxxxxxxxxxxx Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/media/usb/uvc/uvc_driver.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c index 775d67720648..6367ee9c0066 100644 --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -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; -- 2.43.0
