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authorTaehee Yoo <ap420073@gmail.com>2019-11-21 12:26:45 +0000
committerJohannes Berg <johannes.berg@intel.com>2019-11-22 13:36:25 +0100
commitbc71d8b580ba81b55b6e15b1c0320632515b4bac (patch)
tree4c4756b2651e1108e2d9391fd52ed7887b575c9f /drivers/net/wireless
parent08a5bdde3812993cb8eb7aa9124703df0de28e4b (diff)
downloadlinux-bc71d8b580ba81b55b6e15b1c0320632515b4bac.tar.bz2
virt_wifi: fix use-after-free in virt_wifi_newlink()
When virt_wifi interface is created, virt_wifi_newlink() is called and it calls register_netdevice(). if register_netdevice() fails, it internally would call ->priv_destructor(), which is virt_wifi_net_device_destructor() and it frees netdev. but virt_wifi_newlink() still use netdev. So, use-after-free would occur in virt_wifi_newlink(). Test commands: ip link add dummy0 type dummy modprobe bonding ip link add bonding_masters link dummy0 type virt_wifi Splat looks like: [ 202.220554] BUG: KASAN: use-after-free in virt_wifi_newlink+0x88b/0x9a0 [virt_wifi] [ 202.221659] Read of size 8 at addr ffff888061629cb8 by task ip/852 [ 202.222896] CPU: 1 PID: 852 Comm: ip Not tainted 5.4.0-rc5 #3 [ 202.223765] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 202.225073] Call Trace: [ 202.225532] dump_stack+0x7c/0xbb [ 202.226869] print_address_description.constprop.5+0x1be/0x360 [ 202.229362] __kasan_report+0x12a/0x16f [ 202.230714] kasan_report+0xe/0x20 [ 202.232595] virt_wifi_newlink+0x88b/0x9a0 [virt_wifi] [ 202.233370] __rtnl_newlink+0xb9f/0x11b0 [ 202.244909] rtnl_newlink+0x65/0x90 [ ... ] Cc: stable@vger.kernel.org Fixes: c7cdba31ed8b ("mac80211-next: rtnetlink wifi simulation device") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://lore.kernel.org/r/20191121122645.9355-1-ap420073@gmail.com [trim stack dump a bit] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers/net/wireless')
-rw-r--r--drivers/net/wireless/virt_wifi.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/virt_wifi.c b/drivers/net/wireless/virt_wifi.c
index 7997cc6de334..01305ba2d3aa 100644
--- a/drivers/net/wireless/virt_wifi.c
+++ b/drivers/net/wireless/virt_wifi.c
@@ -450,7 +450,6 @@ static void virt_wifi_net_device_destructor(struct net_device *dev)
*/
kfree(dev->ieee80211_ptr);
dev->ieee80211_ptr = NULL;
- free_netdev(dev);
}
/* No lock interaction. */
@@ -458,7 +457,7 @@ static void virt_wifi_setup(struct net_device *dev)
{
ether_setup(dev);
dev->netdev_ops = &virt_wifi_ops;
- dev->priv_destructor = virt_wifi_net_device_destructor;
+ dev->needs_free_netdev = true;
}
/* Called in a RCU read critical section from netif_receive_skb */
@@ -544,6 +543,7 @@ static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
goto unregister_netdev;
}
+ dev->priv_destructor = virt_wifi_net_device_destructor;
priv->being_deleted = false;
priv->is_connected = false;
priv->is_up = false;