linux/net/8021q
Ziyang Xuan 563bcbae3b 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: 1da177e4c3 ("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>
2021-11-03 14:19:23 +00:00
..
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
vlan_core.c vlan/8021q: avoid retpoline overhead on GRO 2021-03-18 19:51:12 -07:00
vlan_dev.c net: vlan: fix a UAF in vlan_dev_real_dev() 2021-11-03 14:19:23 +00:00
vlan_gvrp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vlan_mvrp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vlan_netlink.c vlan: vlan_changelink() should propagate errors 2020-01-07 13:35:14 -08:00
vlan.c net: vlan: fix a UAF in vlan_dev_real_dev() 2021-11-03 14:19:23 +00:00
vlan.h net: vlan: pass thru all GSO_SOFTWARE in hw_enc_features 2021-06-18 11:58:03 -07:00
vlanproc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
vlanproc.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00