synclink: fix info leak in ioctl

The hdlcdev_ioctl() code fails to initialize the two padding bytes of
struct sync_serial_settings after the ->loopback member. Add an explicit
memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Salva Peiró <speiro@ai2.upv.es>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 2 insertions, 0 deletions

diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index 5ae14b46cce0..d48e040cd8c5 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -7866,6 +7866,7 @@ static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                                               HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
                                               HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
 
+                memset(&new_line, 0, sizeof(new_line));
                 switch (flags){
                 case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
                 case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index 144202eef6fe..53ba8537de8d 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -1766,6 +1766,7 @@ static int hdlcdev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                                               HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
                                               HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
 
+                memset(&new_line, 0, sizeof(new_line));
                 switch (flags){
                 case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
                 case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;