diff options
| author | Ziyang Xuan <william.xuanziyang@huawei.com> | 2021-11-02 10:12:18 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-11-03 14:19:23 +0000 |
| commit | 563bcbae3ba233c275c244bfce2efe12938f5363 (patch) | |
| tree | 55560cd4c436e99819b9d2c7534a95dcb40268f1 | |
| parent | 250962e4684678629afd2feeaefdc40c5db501f4 (diff) | |
net: vlan: fix a UAF in vlan_dev_real_dev()
The real_dev of a vlan net_device may be freed after
unregister_vlan_dev(). Access the real_dev continually by
vlan_dev_real_dev() will trigger the UAF problem for the
real_dev like following:
==================================================================
BUG: KASAN: use-after-free in vlan_dev_real_dev+0xf9/0x120
Call Trace:
kasan_report.cold+0x83/0xdf
vlan_dev_real_dev+0xf9/0x120
is_eth_port_of_netdev_filter.part.0+0xb1/0x2c0
is_eth_port_of_netdev_filter+0x28/0x40
ib_enum_roce_netdev+0x1a3/0x300
ib_enum_all_roce_netdevs+0xc7/0x140
netdevice_event_work_handler+0x9d/0x210
...
Freed by task 9288:
kasan_save_stack+0x1b/0x40
kasan_set_track+0x1c/0x30
kasan_set_free_info+0x20/0x30
__kasan_slab_free+0xfc/0x130
slab_free_freelist_hook+0xdd/0x240
kfree+0xe4/0x690
kvfree+0x42/0x50
device_release+0x9f/0x240
kobject_put+0x1c8/0x530
put_device+0x1b/0x30
free_netdev+0x370/0x540
ppp_destroy_interface+0x313/0x3d0
...
Move the put_device(real_dev) to vlan_dev_free(). Ensure
real_dev not be freed before vlan_dev unregistered.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+e4df4e1389e28972e955@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/8021q/vlan.c | 3 | ||||
| -rw-r--r-- | net/8021q/vlan_dev.c | 3 |
2 files changed, 3 insertions, 3 deletions
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 55275ef9a31a..a3a0a5e994f5 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -123,9 +123,6 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) } vlan_vid_del(real_dev, vlan->vlan_proto, vlan_id); - - /* Get rid of the vlan's reference to real_dev */ - dev_put(real_dev); } int vlan_check_real_dev(struct net_device *real_dev, diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 90330b893134..ab6dee28536d 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -843,6 +843,9 @@ static void vlan_dev_free(struct net_device *dev) free_percpu(vlan->vlan_pcpu_stats); vlan->vlan_pcpu_stats = NULL; + + /* Get rid of the vlan's reference to real_dev */ + dev_put(vlan->real_dev); } void vlan_setup(struct net_device *dev) |