Re: [PATCH 5.10.y] media: uvcvideo: Fix integer overflow calculating timestamp

[Greg KH <greg@kroah.com>]

On Mon, Aug 19, 2024 at 12:06:52PM +0000, Ricardo Ribalda wrote:
> The function uvc_video_clock_update() supports a single SOF overflow. Or
> in other words, the maximum difference between the first ant the last
> timestamp can be 4096 ticks or 4.096 seconds.
> 
> This results in a maximum value for y2 of: 0x12FBECA00, that overflows
> 32bits.
> y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;
> 
> Extend the size of y2 to u64 to support all its values.
> 
> Without this patch:
>  # yavta -s 1920x1080 -f YUYV -t 1/5 -c /dev/video0
> Device /dev/v4l/by-id/usb-Shine-Optics_Integrated_Camera_0001-video-index0 opened.
> Device `Integrated Camera: Integrated C' on `usb-0000:00:14.0-6' (driver 'uvcvideo') supports video, capture, without mplanes.
> Video format set: YUYV (56595559) 1920x1080 (stride 3840) field none buffer size 4147200
> Video format: YUYV (56595559) 1920x1080 (stride 3840) field none buffer size 4147200
> Current frame rate: 1/5
> Setting frame rate to: 1/5
> Frame rate set: 1/5
> 8 buffers requested.
> length: 4147200 offset: 0 timestamp type/source: mono/SoE
> Buffer 0/0 mapped at address 0x7947ea94c000.
> length: 4147200 offset: 4149248 timestamp type/source: mono/SoE
> Buffer 1/0 mapped at address 0x7947ea557000.
> length: 4147200 offset: 8298496 timestamp type/source: mono/SoE
> Buffer 2/0 mapped at address 0x7947ea162000.
> length: 4147200 offset: 12447744 timestamp type/source: mono/SoE
> Buffer 3/0 mapped at address 0x7947e9d6d000.
> length: 4147200 offset: 16596992 timestamp type/source: mono/SoE
> Buffer 4/0 mapped at address 0x7947e9978000.
> length: 4147200 offset: 20746240 timestamp type/source: mono/SoE
> Buffer 5/0 mapped at address 0x7947e9583000.
> length: 4147200 offset: 24895488 timestamp type/source: mono/SoE
> Buffer 6/0 mapped at address 0x7947e918e000.
> length: 4147200 offset: 29044736 timestamp type/source: mono/SoE
> Buffer 7/0 mapped at address 0x7947e8d99000.
> 0 (0) [-] none 0 4147200 B 507.554210 508.874282 242.836 fps ts mono/SoE
> 1 (1) [-] none 2 4147200 B 508.886298 509.074289 0.751 fps ts mono/SoE
> 2 (2) [-] none 3 4147200 B 509.076362 509.274307 5.261 fps ts mono/SoE
> 3 (3) [-] none 4 4147200 B 509.276371 509.474336 5.000 fps ts mono/SoE
> 4 (4) [-] none 5 4147200 B 509.476394 509.674394 4.999 fps ts mono/SoE
> 5 (5) [-] none 6 4147200 B 509.676506 509.874345 4.997 fps ts mono/SoE
> 6 (6) [-] none 7 4147200 B 509.876430 510.074370 5.002 fps ts mono/SoE
> 7 (7) [-] none 8 4147200 B 510.076434 510.274365 5.000 fps ts mono/SoE
> 8 (0) [-] none 9 4147200 B 510.276421 510.474333 5.000 fps ts mono/SoE
> 9 (1) [-] none 10 4147200 B 510.476391 510.674429 5.001 fps ts mono/SoE
> 10 (2) [-] none 11 4147200 B 510.676434 510.874283 4.999 fps ts mono/SoE
> 11 (3) [-] none 12 4147200 B 510.886264 511.074349 4.766 fps ts mono/SoE
> 12 (4) [-] none 13 4147200 B 511.070577 511.274304 5.426 fps ts mono/SoE
> 13 (5) [-] none 14 4147200 B 511.286249 511.474301 4.637 fps ts mono/SoE
> 14 (6) [-] none 15 4147200 B 511.470542 511.674251 5.426 fps ts mono/SoE
> 15 (7) [-] none 16 4147200 B 511.672651 511.874337 4.948 fps ts mono/SoE
> 16 (0) [-] none 17 4147200 B 511.873988 512.074462 4.967 fps ts mono/SoE
> 17 (1) [-] none 18 4147200 B 512.075982 512.278296 4.951 fps ts mono/SoE
> 18 (2) [-] none 19 4147200 B 512.282631 512.482423 4.839 fps ts mono/SoE
> 19 (3) [-] none 20 4147200 B 518.986637 512.686333 0.149 fps ts mono/SoE
> 20 (4) [-] none 21 4147200 B 518.342709 512.886386 -1.553 fps ts mono/SoE
> 21 (5) [-] none 22 4147200 B 517.909812 513.090360 -2.310 fps ts mono/SoE
> 22 (6) [-] none 23 4147200 B 517.590775 513.294454 -3.134 fps ts mono/SoE
> 23 (7) [-] none 24 4147200 B 513.298465 513.494335 -0.233 fps ts mono/SoE
> 24 (0) [-] none 25 4147200 B 513.510273 513.698375 4.721 fps ts mono/SoE
> 25 (1) [-] none 26 4147200 B 513.698904 513.902327 5.301 fps ts mono/SoE
> 26 (2) [-] none 27 4147200 B 513.895971 514.102348 5.074 fps ts mono/SoE
> 27 (3) [-] none 28 4147200 B 514.099091 514.306337 4.923 fps ts mono/SoE
> 28 (4) [-] none 29 4147200 B 514.310348 514.510567 4.734 fps ts mono/SoE
> 29 (5) [-] none 30 4147200 B 514.509295 514.710367 5.026 fps ts mono/SoE
> 30 (6) [-] none 31 4147200 B 521.532513 514.914398 0.142 fps ts mono/SoE
> 31 (7) [-] none 32 4147200 B 520.885277 515.118385 -1.545 fps ts mono/SoE
> 32 (0) [-] none 33 4147200 B 520.411140 515.318336 -2.109 fps ts mono/SoE
> 33 (1) [-] none 34 4147200 B 515.325425 515.522278 -0.197 fps ts mono/SoE
> 34 (2) [-] none 35 4147200 B 515.538276 515.726423 4.698 fps ts mono/SoE
> 35 (3) [-] none 36 4147200 B 515.720767 515.930373 5.480 fps ts mono/SoE
> 
> Cc: stable@vger.kernel.org
> Fixes: 66847ef013cc ("[media] uvcvideo: Add UVC timestamps support")
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Link: https://lore.kernel.org/r/20240610-hwtimestamp-followup-v1-2-f9eaed7be7f0@chromium.org
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> (cherry picked from commit 8676a5e796fa18f55897ca36a94b2adf7f73ebd1)
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---

All now queued up, thanks.

greg k-h