From 46a8b29c6306d8bbfd92b614ef65a47c900d8e70 Mon Sep 17 00:00:00 2001

From: Pavel Skripkin <paskripkin@gmail.com>

Date: Mon, 24 May 2021 23:02:08 +0300

Subject: [PATCH] net: usb: fix memory leak in smsc75xx_bind

Git-commit: 46a8b29c6306d8bbfd92b614ef65a47c900d8e70

Patch-mainline: v5.13-rc4

References: git-fixes

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>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/net/usb/smsc75xx.c | 8 ++++++--

 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c

index f8cdabb9ef5a..b286993da67c 100644

--- a/drivers/net/usb/smsc75xx.c

+++ b/drivers/net/usb/smsc75xx.c

@@ -1483,7 +1483,7 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)

 	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);

@@ -1492,7 +1492,7 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)

 	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;

@@ -1502,6 +1502,10 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf)

 	dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len;

 	dev->net->max_mtu = MAX_SINGLE_PACKET_SIZE;

 	return 0;

+

+err:

+	kfree(pdata);

+	return ret;

 }

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

-- 

2.26.2