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authorJohan Hovold <johan@kernel.org>2017-01-12 14:56:12 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-14 13:32:56 +0200
commitf15ca928dc2a5118f1dead4060b6fa2c4e5b1576 (patch)
treea71b20bbb4f8b4f3f9d727cbaaa5dbe2f5fd13fa
parent5890ca8333e361a0437fe9962487dd0fbb4db89c (diff)
USB: serial: ftdi_sio: fix latency-timer error handling
commit e3e574ad85a208cb179f33720bb5f12b453de33c upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 19a98116c2ab..b3a21fcbbaf9 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);