From ed0826d1d4bf75fa5d7734e2eb8029cdfd1913bb Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 24 May 2021 13:09:19 +0200 Subject: media: gspca/sunplus: fix zero-length control requests commit b4bb4d425b7b02424afea2dfdcd77b3b4794175e upstream. The direction of the pipe argument must match the request-type direction bit or control requests may fail depending on the host-controller-driver implementation. Control transfers without a data stage are treated as OUT requests by the USB stack and should be using usb_sndctrlpipe(). Failing to do so will now trigger a warning. Fix the single zero-length control request which was using the read-register helper, and update the helper so that zero-length reads fail with an error message instead. Fixes: 6a7eba24e4f0 ("V4L/DVB (8157): gspca: all subdrivers") Cc: stable@vger.kernel.org # 2.6.27 Signed-off-by: Johan Hovold Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/gspca/sunplus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/media/usb/gspca/sunplus.c') diff --git a/drivers/media/usb/gspca/sunplus.c b/drivers/media/usb/gspca/sunplus.c index cc3e1478c5a0..949915734d57 100644 --- a/drivers/media/usb/gspca/sunplus.c +++ b/drivers/media/usb/gspca/sunplus.c @@ -255,6 +255,10 @@ static void reg_r(struct gspca_dev *gspca_dev, PERR("reg_r: buffer overflow\n"); return; } + if (len == 0) { + PERR("reg_r: zero-length read\n"); + return; + } if (gspca_dev->usb_err < 0) return; ret = usb_control_msg(gspca_dev->dev, @@ -263,7 +267,7 @@ static void reg_r(struct gspca_dev *gspca_dev, USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, 0, /* value */ index, - len ? gspca_dev->usb_buf : NULL, len, + gspca_dev->usb_buf, len, 500); if (ret < 0) { pr_err("reg_r err %d\n", ret); @@ -739,7 +743,7 @@ static int sd_start(struct gspca_dev *gspca_dev) case MegaImageVI: reg_w_riv(gspca_dev, 0xf0, 0, 0); spca504B_WaitCmdStatus(gspca_dev); - reg_r(gspca_dev, 0xf0, 4, 0); + reg_w_riv(gspca_dev, 0xf0, 4, 0); spca504B_WaitCmdStatus(gspca_dev); break; default: -- cgit v1.2.3