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| author | Johan Hovold <johan@kernel.org> | 2021-05-24 14:09:19 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2021-06-02 15:15:01 +0300 |
| commit | b4bb4d425b7b02424afea2dfdcd77b3b4794175e (patch) | |
| tree | 7200cde5042cb2244c868229e07de23bbb36abde /drivers/media/usb | |
| parent | 8ed339f23d41e21660a389adf2e7b2966d457ff6 (diff) | |
| download | linux-b4bb4d425b7b02424afea2dfdcd77b3b4794175e.tar.xz | |
media: gspca/sunplus: fix zero-length control requests
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 <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'drivers/media/usb')
| -rw-r--r-- | drivers/media/usb/gspca/sunplus.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/media/usb/gspca/sunplus.c b/drivers/media/usb/gspca/sunplus.c index ace3da40006e..971dee0a56da 100644 --- a/drivers/media/usb/gspca/sunplus.c +++ b/drivers/media/usb/gspca/sunplus.c @@ -242,6 +242,10 @@ static void reg_r(struct gspca_dev *gspca_dev, gspca_err(gspca_dev, "reg_r: buffer overflow\n"); return; } + if (len == 0) { + gspca_err(gspca_dev, "reg_r: zero-length read\n"); + return; + } if (gspca_dev->usb_err < 0) return; ret = usb_control_msg(gspca_dev->dev, @@ -250,7 +254,7 @@ 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); @@ -727,7 +731,7 @@ 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: |