Messages in this thread | | | Date | Wed, 3 Nov 2021 10:50:34 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH net v2] net: vlan: fix a UAF in vlan_dev_real_dev() |
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On Tue, Nov 02, 2021 at 10:12:18AM +0800, Ziyang Xuan wrote: > 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> > --- > net/8021q/vlan.c | 3 --- > net/8021q/vlan_dev.c | 3 +++ > 2 files changed, 3 insertions(+), 3 deletions(-)
Suggested-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
(though I can't tell either if there is a possiblecircular dep problem in some oddball case)
Jason
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