When a vlan netdev enter netdevice_event process although it is not a
roce netdev, it will be passed to netdevice_event_work_handler() to
process. In order to hold the netdev of netdevice_event after
netdevice_event() return, call dev_hold() to hold the netdev in
netdevice_queue_work(). But that did not consider the real_dev of a vlan
netdev, the real_dev can be freed within netdevice_event_work_handler()
be scheduled. It would trigger the UAF problem for the real_dev like
following:
==================================================================
BUG: KASAN: use-after-free in vlan_dev_real_dev+0xf9/0x120
Read of size 4 at addr ffff88801648a0c4 by task kworker/u8:0/8
Workqueue: gid-cache-wq netdevice_event_work_handler
Call Trace:
dump_stack_lvl+0xcd/0x134
print_address_description.constprop.0.cold+0x93/0x334
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
...
Allocated by task 9289:
kasan_save_stack+0x1b/0x40
__kasan_kmalloc+0x9b/0xd0
__kmalloc_node+0x20a/0x330
kvmalloc_node+0x61/0xf0
alloc_netdev_mqs+0x9d/0x1140
rtnl_create_link+0x955/0xb70
__rtnl_newlink+0xe10/0x15b0
rtnl_newlink+0x64/0xa0
...
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
ppp_release+0x1bf/0x240
...
Hold the real_dev for a vlan netdev in netdevice_event_work_handler()
to fix the UAF problem.
Fixes: 238fdf48f2b5 ("IB/core: Add RoCE table bonding support")
Reported-by: syzbot+e4df4e1389e28972e955@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
---
drivers/infiniband/core/roce_gid_mgmt.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/core/roce_gid_mgmt.c b/drivers/infiniband/core/roce_gid_mgmt.c
index 68197e576433..063dbe72b7c2 100644
--- a/drivers/infiniband/core/roce_gid_mgmt.c
+++ b/drivers/infiniband/core/roce_gid_mgmt.c
@@ -621,6 +621,7 @@ static void netdevice_event_work_handler(struct work_struct *_work)
{
struct netdev_event_work *work =
container_of(_work, struct netdev_event_work, work);
+ struct net_device *real_dev;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(work->cmds) && work->cmds[i].cb; i++) {
@@ -628,6 +629,12 @@ static void netdevice_event_work_handler(struct work_struct *_work)
work->cmds[i].filter_ndev,
work->cmds[i].cb,
work->cmds[i].ndev);
+ real_dev = rdma_vlan_dev_real_dev(work->cmds[i].ndev);
+ if (real_dev)
+ dev_put(real_dev);
+ real_dev = rdma_vlan_dev_real_dev(work->cmds[i].filter_ndev);
+ if (real_dev)
+ dev_put(real_dev);
dev_put(work->cmds[i].ndev);
dev_put(work->cmds[i].filter_ndev);
}
@@ -638,9 +645,10 @@ static void netdevice_event_work_handler(struct work_struct *_work)
static int netdevice_queue_work(struct netdev_event_work_cmd *cmds,
struct net_device *ndev)
{
- unsigned int i;
struct netdev_event_work *ndev_work =
kmalloc(sizeof(*ndev_work), GFP_KERNEL);
+ struct net_device *real_dev;
+ unsigned int i;
if (!ndev_work)
return NOTIFY_DONE;
@@ -653,6 +661,12 @@ static int netdevice_queue_work(struct netdev_event_work_cmd *cmds,
ndev_work->cmds[i].filter_ndev = ndev;
dev_hold(ndev_work->cmds[i].ndev);
dev_hold(ndev_work->cmds[i].filter_ndev);
+ real_dev = rdma_vlan_dev_real_dev(ndev_work->cmds[i].ndev);
+ if (real_dev)
+ dev_hold(real_dev);
+ real_dev = rdma_vlan_dev_real_dev(ndev_work->cmds[i].filter_ndev);
+ if (real_dev)
+ dev_hold(real_dev);
}
INIT_WORK(&ndev_work->work, netdevice_event_work_handler);
--
2.25.1
