On Mon, May 24, 2021 at 01:09:20PM +0200, Johan Hovold wrote:
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 zero-length i2c-read request used for type detection by attempting to read a single byte instead.
Reported-by: syzbot+faf11bbadc5a372564da@syzkaller.appspotmail.com Fixes: d0f232e823af ("[media] rtl28xxu: add heuristic to detect chip type") Cc: stable@vger.kernel.org # 4.0 Cc: Antti Palosaari crope@iki.fi Signed-off-by: Johan Hovold johan@kernel.org
drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c index 97ed17a141bb..2c04ed8af0e4 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c @@ -612,8 +612,9 @@ static int rtl28xxu_read_config(struct dvb_usb_device *d) static int rtl28xxu_identify_state(struct dvb_usb_device *d, const char **name) { struct rtl28xxu_dev *dev = d_to_priv(d);
- u8 buf[1]; int ret;
- struct rtl28xxu_req req_demod_i2c = {0x0020, CMD_I2C_DA_RD, 0, NULL};
- struct rtl28xxu_req req_demod_i2c = {0x0020, CMD_I2C_DA_RD, 1, buf};
dev_dbg(&d->intf->dev, "\n");
As reported here
https://lore.kernel.org/r/YLSVsrhMZ2oOL1vM@hovoldconsulting.com
this patch is causing the chip type to no longer be detected correctly, so please drop this one for now until this has been resolved.
Johan