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authorJohan Hovold <johan@kernel.org>2017-01-12 14:56:16 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-14 14:00:19 +0200
commit62b8b773ebde042ef7e016c9bed6327306885fee (patch)
tree1670b3eabe059450dab9dcbe87f8b343a7e618e1
parente17c48c3280e70dc5c8a9d579613ea732591dedf (diff)
USB: serial: mct_u232: fix modem-status error handling
commit 36356a669eddb32917fc4b5c2b9b8bf80ede69de upstream. Make sure to detect short control-message transfers so that errors are logged when reading the modem status at open. Note that while this also avoids initialising the modem status using uninitialised heap data, these bits could not leak to user space as they are currently not used. 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/mct_u232.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index 885655315de1..edbc81f205c2 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -322,8 +322,12 @@ static int mct_u232_get_modem_stat(struct usb_serial_port *port,
MCT_U232_GET_REQUEST_TYPE,
0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
WDR_TIMEOUT);
- if (rc < 0) {
+ if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
+
+ if (rc >= 0)
+ rc = -EIO;
+
*msr = 0;
} else {
*msr = buf[0];