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authorJohan Hovold <johan@kernel.org>2017-01-12 14:56:12 +0100
committerJohan Hovold <johan@kernel.org>2017-01-16 16:38:55 +0100
commite3e574ad85a208cb179f33720bb5f12b453de33c (patch)
tree0e59dd12fad710a7eec5403a548915dd03e96cd1 /drivers
parentUSB: serial: ftdi_sio: fix modem-status error handling (diff)
downloadlinux-e3e574ad85a208cb179f33720bb5f12b453de33c.tar.xz
linux-e3e574ad85a208cb179f33720bb5f12b453de33c.zip
USB: serial: ftdi_sio: fix latency-timer error handling
Make sure to detect short responses when reading the latency timer to avoid using stale buffer data. Note that no heap data would currently leak through sysfs as ASYNC_LOW_LATENCY is set by default. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/serial/ftdi_sio.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 6dee20fc7e45..b064fad8e3ee 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1439,10 +1439,13 @@ static int read_latency_timer(struct usb_serial_port *port)
FTDI_SIO_GET_LATENCY_TIMER_REQUEST_TYPE,
0, priv->interface,
buf, 1, WDR_TIMEOUT);
- if (rv < 0)
+ if (rv < 1) {
dev_err(&port->dev, "Unable to read latency timer: %i\n", rv);
- else
+ if (rv >= 0)
+ rv = -EIO;
+ } else {
priv->latency = buf[0];
+ }
kfree(buf);