[PATCH 4.9 29/71] net: usb: fix possible use-after-free in smsc75xx_bind
From: Sasha Levin <sashal@kernel.org>
Date: 2021-06-28 15:19:35
Also in:
lkml
Subsystem:
networking drivers, the rest, usb networking drivers, usb smsc75xx ethernet driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Steve Glendinning
From: Dongliang Mu <redacted>
[ Upstream commit 56b786d86694e079d8aad9b314e015cd4ac02a3d ]
The commit 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind")
fails to clean up the work scheduled in smsc75xx_reset->
smsc75xx_set_multicast, which leads to use-after-free if the work is
scheduled to start after the deallocation. In addition, this patch
also removes a dangling pointer - dev->data[0].
This patch calls cancel_work_sync to cancel the scheduled work and set
the dangling pointer to NULL.
Fixes: 46a8b29c6306 ("net: usb: fix memory leak in smsc75xx_bind")
Signed-off-by: Dongliang Mu <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/smsc75xx.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index 3a391ae5c4e0..841d97491592 100644
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c@@ -1497,7 +1497,7 @@ 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"); - goto err; + goto free_pdata; } smsc75xx_init_mac_address(dev);
@@ -1506,7 +1506,7 @@ 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); - goto err; + goto cancel_work; } dev->net->netdev_ops = &smsc75xx_netdev_ops;
@@ -1516,8 +1516,11 @@ static int smsc75xx_bind(struct usbnet *dev, struct usb_interface *intf) dev->hard_mtu = dev->net->mtu + dev->net->hard_header_len; return 0; -err: +cancel_work: + cancel_work_sync(&pdata->set_multicast); +free_pdata: kfree(pdata); + dev->data[0] = 0; return ret; }
@@ -1528,7 +1531,6 @@ static void smsc75xx_unbind(struct usbnet *dev, struct usb_interface *intf) cancel_work_sync(&pdata->set_multicast); netif_dbg(dev, ifdown, dev->net, "free pdata\n"); kfree(pdata); - pdata = NULL; dev->data[0] = 0; } }
--
2.30.2