From: Taehee Yoo ap420073@gmail.com
[ Upstream commit 037f9cdf72fb8a7ff9ec2b5dd05336ec1492bdf1 ]
netdev_upper_dev_link() is useful to manage lower/upper interfaces. And this function internally validates looping, maximum depth. All or most virtual interfaces that could have a real interface (e.g. macsec, macvlan, ipvlan etc.) use lower/upper infrastructure.
Test commands: modprobe rmnet ip link add dummy0 type dummy ip link add rmnet1 link dummy0 type rmnet mux_id 1 for i in {2..100} do let A=$i-1 ip link add rmnet$i link rmnet$A type rmnet mux_id $i done ip link del dummy0
The purpose of the test commands is to make stack overflow.
Splat looks like: [ 52.411438][ T1395] BUG: KASAN: slab-out-of-bounds in find_busiest_group+0x27e/0x2c00 [ 52.413218][ T1395] Write of size 64 at addr ffff8880c774bde0 by task ip/1395 [ 52.414841][ T1395] [ 52.430720][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.496511][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.513597][ T1395] Call Trace: [ 52.546516][ T1395] [ 52.558773][ T1395] Allocated by task 3171537984: [ 52.588290][ T1395] BUG: unable to handle page fault for address: ffffffffb999e260 [ 52.589311][ T1395] #PF: supervisor read access in kernel mode [ 52.590529][ T1395] #PF: error_code(0x0000) - not-present page [ 52.591374][ T1395] PGD d6818067 P4D d6818067 PUD d6819063 PMD 0 [ 52.592288][ T1395] Thread overran stack, or stack corrupted [ 52.604980][ T1395] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 52.605856][ T1395] CPU: 1 PID: 1395 Comm: ip Not tainted 5.6.0-rc1+ #447 [ 52.611764][ T1395] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 52.621520][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.622296][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 52.627887][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 52.628735][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 52.631773][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 52.649584][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 52.674857][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 52.678257][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 52.694541][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 52.764039][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 52.815008][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 52.862312][ T1395] Call Trace: [ 52.887133][ T1395] Modules linked in: dummy rmnet veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_dex [ 52.936749][ T1395] CR2: ffffffffb999e260 [ 52.965695][ T1395] ---[ end trace 7e32ca99482dbb31 ]--- [ 52.966556][ T1395] RIP: 0010:stack_depot_fetch+0x10/0x30 [ 52.971083][ T1395] Code: ff e9 f9 fe ff ff 48 89 df e8 9c 1d 91 ff e9 ca fe ff ff cc cc cc cc cc cc cc 89 f8 0 [ 53.003650][ T1395] RSP: 0018:ffff8880c774bb60 EFLAGS: 00010006 [ 53.043183][ T1395] RAX: 00000000001f8880 RBX: ffff8880c774d140 RCX: 0000000000000000 [ 53.076480][ T1395] RDX: 000000000000001d RSI: ffff8880c774bb68 RDI: 0000000000003ff0 [ 53.093858][ T1395] RBP: ffffea00031dd200 R08: ffffed101b43e403 R09: ffffed101b43e403 [ 53.112795][ T1395] R10: 0000000000000001 R11: ffffed101b43e402 R12: ffff8880d900e5c0 [ 53.139837][ T1395] R13: ffff8880c774c000 R14: 0000000000000000 R15: dffffc0000000000 [ 53.141500][ T1395] FS: 00007fe867f6e0c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 [ 53.143343][ T1395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 53.152007][ T1395] CR2: ffffffffb999e260 CR3: 00000000c26aa005 CR4: 00000000000606e0 [ 53.156459][ T1395] Kernel panic - not syncing: Fatal exception [ 54.213570][ T1395] Shutting down cpus with NMI [ 54.354112][ T1395] Kernel Offset: 0x33000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0x) [ 54.355687][ T1395] Rebooting in 5 seconds..
Fixes: b37f78f234bf ("net: qualcomm: rmnet: Fix crash on real dev unregistration") Signed-off-by: Taehee Yoo ap420073@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- .../ethernet/qualcomm/rmnet/rmnet_config.c | 35 +++++++++---------- 1 file changed, 16 insertions(+), 19 deletions(-)
diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c index 3c0e6d24d0834..e3fbf2331b965 100644 --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c @@ -61,9 +61,6 @@ static int rmnet_unregister_real_device(struct net_device *real_dev,
kfree(port);
- /* release reference on real_dev */ - dev_put(real_dev); - netdev_dbg(real_dev, "Removed from rmnet\n"); return 0; } @@ -89,9 +86,6 @@ static int rmnet_register_real_device(struct net_device *real_dev) return -EBUSY; }
- /* hold on to real dev for MAP data */ - dev_hold(real_dev); - for (entry = 0; entry < RMNET_MAX_LOGICAL_EP; entry++) INIT_HLIST_HEAD(&port->muxed_ep[entry]);
@@ -162,6 +156,10 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev, if (err) goto err1;
+ err = netdev_upper_dev_link(real_dev, dev, extack); + if (err < 0) + goto err2; + port->rmnet_mode = mode;
hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]); @@ -178,6 +176,8 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev,
return 0;
+err2: + unregister_netdevice(dev); err1: rmnet_unregister_real_device(real_dev, port); err0: @@ -209,33 +209,30 @@ static void rmnet_dellink(struct net_device *dev, struct list_head *head) rmnet_vnd_dellink(mux_id, port, ep); kfree(ep); } + netdev_upper_dev_unlink(real_dev, dev); rmnet_unregister_real_device(real_dev, port);
unregister_netdevice_queue(dev, head); }
-static void rmnet_force_unassociate_device(struct net_device *dev) +static void rmnet_force_unassociate_device(struct net_device *real_dev) { - struct net_device *real_dev = dev; struct hlist_node *tmp_ep; struct rmnet_endpoint *ep; struct rmnet_port *port; unsigned long bkt_ep; LIST_HEAD(list);
- if (!rmnet_is_real_dev_registered(real_dev)) - return; - ASSERT_RTNL();
- port = rmnet_get_port_rtnl(dev); + port = rmnet_get_port_rtnl(real_dev);
- rmnet_unregister_bridge(dev, port); + rmnet_unregister_bridge(real_dev, port);
hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) { + netdev_upper_dev_unlink(real_dev, ep->egress_dev); unregister_netdevice_queue(ep->egress_dev, &list); rmnet_vnd_dellink(ep->mux_id, port, ep); - hlist_del_init_rcu(&ep->hlnode); kfree(ep); } @@ -248,15 +245,15 @@ static void rmnet_force_unassociate_device(struct net_device *dev) static int rmnet_config_notify_cb(struct notifier_block *nb, unsigned long event, void *data) { - struct net_device *dev = netdev_notifier_info_to_dev(data); + struct net_device *real_dev = netdev_notifier_info_to_dev(data);
- if (!dev) + if (!rmnet_is_real_dev_registered(real_dev)) return NOTIFY_DONE;
switch (event) { case NETDEV_UNREGISTER: - netdev_dbg(dev, "Kernel unregister\n"); - rmnet_force_unassociate_device(dev); + netdev_dbg(real_dev, "Kernel unregister\n"); + rmnet_force_unassociate_device(real_dev); break;
default: @@ -477,8 +474,8 @@ static int __init rmnet_init(void)
static void __exit rmnet_exit(void) { - unregister_netdevice_notifier(&rmnet_dev_notifier); rtnl_link_unregister(&rmnet_link_ops); + unregister_netdevice_notifier(&rmnet_dev_notifier); }
module_init(rmnet_init)