[PATCH 4.4 19/54] net: usb: fix memory leak in smsc75xx_bind

Greg Kroah-Hartman
2021-05-31T13:17:23Z

From: Pavel Skripkin <paskripkin@gmail.com>

commit 46a8b29c6306d8bbfd92b614ef65a47c900d8e70 upstream.

Syzbot reported memory leak in smsc75xx_bind().
The problem was is non-freed memory in case of
errors after memory allocation.

backtrace:
[<ffffffff84245b62>] kmalloc include/linux/slab.h:556 [inline]
[<ffffffff84245b62>] kzalloc include/linux/slab.h:686 [inline]
[<ffffffff84245b62>] smsc75xx_bind+0x7a/0x334 drivers/net/usb/smsc75xx.c:1460
[<ffffffff82b5b2e6>] usbnet_probe+0x3b6/0xc30 drivers/net/usb/usbnet.c:1728

Fixes: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Cc: stable@kernel.vger.org
Reported-and-tested-by: syzbot+b558506ba8165425fee2@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/usb/smsc75xx.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -1485,7 +1485,7 @@ static int smsc75xx_bind(struct usbnet *
ret = smsc75xx_wait_ready(dev, 0);
if (ret < 0) {
netdev_warn(dev->net, "device not ready in smsc75xx_bind\n");
- return ret;
+ goto err;
}

smsc75xx_init_mac_address(dev);
@@ -1494,7 +1494,7 @@ static int smsc75xx_bind(struct usbnet *
ret = smsc75xx_reset(dev);
if (ret < 0) {
netdev_warn(dev->net, "smsc75xx_reset error %d\n", ret);
- return ret;
+ goto err;
}

dev->net->netdev_ops = &smsc75xx_netdev_ops;
@@ -1503,6 +1503,10 @@ static int smsc75xx_bind(struct usbnet *
dev->net->hard_header_len += SMSC75XX_TX_OVERHEAD;
dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;
return 0;
+
+err:
+ kfree(pdata);
+ return ret;
}

static void smsc75xx_unbind(struct usbnet *dev, struct usb_interface *intf)