From e25b9f0712263d60cb04aefa7fd8d7c448bc97cb Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Wed, 14 Jan 2026 10:32:13 +0000 Subject: [PATCH] media: uvcvideo: Fix allocation for small frame sizes [ Upstream commit 40d3ac25c11310bfaa50ed7614846ef75cb69a1e ] If a frame has size of less or equal than one packet size uvc_alloc_urb_buffers() is unable to allocate memory for it due to a off-by-one error. Fix the off-by-one-error and now that we are at it, make sure that stream->urb_size has always a valid value when we return from the function, even when an error happens. Fixes: efdc8a9585ce ("V4L/DVB (10295): uvcvideo: Retry URB buffers allocation when the system is low on memory.") Reported-by: Itay Chamiel Closes: https://lore.kernel.org/linux-media/CANiDSCsSoZf2LsCCoWAUbCg6tJT-ypXR1B85aa6rAdMVYr2iBQ@mail.gmail.com/T/#t Co-developed-by: Itay Chamiel Signed-off-by: Itay Chamiel Signed-off-by: Ricardo Ribalda Reviewed-by: Laurent Pinchart Tested-by: Itay Chamiel Link: https://patch.msgid.link/20260114-uvc-alloc-urb-v1-1-cedf3fb66711@chromium.org Signed-off-by: Laurent Pinchart Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/uvc/uvc_video.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index 57e6f9af536f..57bccbf17f6d 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1842,7 +1842,7 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, npackets = UVC_MAX_PACKETS; /* Retry allocations until one succeed. */ - for (; npackets > 1; npackets /= 2) { + for (; npackets > 0; npackets /= 2) { stream->urb_size = psize * npackets; for (i = 0; i < UVC_URBS; ++i) { @@ -1867,6 +1867,7 @@ static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, uvc_dbg(stream->dev, VIDEO, "Failed to allocate URB buffers (%u bytes per packet)\n", psize); + stream->urb_size = 0; return 0; }