Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 22/32] USB: serial: spcp8x5: fix modem-status handling | Date | Fri, 24 Feb 2017 09:38:06 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold <johan@kernel.org>
commit 5ed8d41023751bdd3546f2fe4118304357efe8d2 upstream.
Make sure to detect short control transfers and return zero on success when retrieving the modem status.
This fixes the TIOCMGET implementation which since e1ed212d8593 ("USB: spcp8x5: add proper modem-status support") has returned TIOCM_LE on successful retrieval, and avoids leaking bits from the stack on short transfers.
This also fixes the carrier-detect implementation which since the above mentioned commit unconditionally has returned true.
Fixes: e1ed212d8593 ("USB: spcp8x5: add proper modem-status support") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/serial/spcp8x5.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/usb/serial/spcp8x5.c +++ b/drivers/usb/serial/spcp8x5.c @@ -232,11 +232,17 @@ static int spcp8x5_get_msr(struct usb_se ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), GET_UART_STATUS, GET_UART_STATUS_TYPE, 0, GET_UART_STATUS_MSR, buf, 1, 100); - if (ret < 0) + if (ret < 1) { dev_err(&port->dev, "failed to get modem status: %d\n", ret); + if (ret >= 0) + ret = -EIO; + goto out; + } dev_dbg(&port->dev, "0xc0:0x22:0:6 %d - 0x02%x\n", ret, *buf); *status = *buf; + ret = 0; +out: kfree(buf); return ret;
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