Andrew Lunn 1bc4e2b000 batman-adv: Avoid endless loop in bat-on-bat netdevice check ... batman-adv checks in different situation if a new device is already on top of a different batman-adv device. This is done by getting the iflink of a device and all its parent. It assumes that this iflink is always a parent device in an acyclic graph. But this assumption is broken by devices like veth which are actually a pair of two devices linked to each other. The recursive check would therefore get veth0 when calling dev_get_iflink on veth1. And it gets veth0 when calling dev_get_iflink with veth1. Creating a veth pair and loading batman-adv freezes parts of the system ip link add veth0 type veth peer name veth1 modprobe batman-adv An RCU stall will be detected on the system which cannot be fixed. INFO: rcu_sched self-detected stall on CPU 1: (5264 ticks this GP) idle=3e9/140000000000001/0 softirq=144683/144686 fqs=5249 (t=5250 jiffies g=46 c=45 q=43) Task dump for CPU 1: insmod R running task 0 247 245 0x00000008 ffffffff8151f140 ffffffff8107888e ffff88000fd141c0 ffffffff8151f140 0000000000000000 ffffffff81552df0 ffffffff8107b420 0000000000000001 ffff88000e3fa700 ffffffff81540b00 ffffffff8107d667 0000000000000001 Call Trace: <IRQ> [<ffffffff8107888e>] ? rcu_dump_cpu_stacks+0x7e/0xd0 [<ffffffff8107b420>] ? rcu_check_callbacks+0x3f0/0x6b0 [<ffffffff8107d667>] ? hrtimer_run_queues+0x47/0x180 [<ffffffff8107cf9d>] ? update_process_times+0x2d/0x50 [<ffffffff810873fb>] ? tick_handle_periodic+0x1b/0x60 [<ffffffff810290ae>] ? smp_trace_apic_timer_interrupt+0x5e/0x90 [<ffffffff813bbae2>] ? apic_timer_interrupt+0x82/0x90 <EOI> [<ffffffff812c3fd7>] ? __dev_get_by_index+0x37/0x40 [<ffffffffa0031f3e>] ? batadv_hard_if_event+0xee/0x3a0 [batman_adv] [<ffffffff812c5801>] ? register_netdevice_notifier+0x81/0x1a0 [...] This can be avoided by checking if two devices are each others parent and stopping the check in this situation. Fixes: b7eddd0b39 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface") Signed-off-by: Andrew Lunn <andrew@lunn.ch> [sven@narfation.org: rewritten description, extracted fix] Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc>		2016-02-16 22:16:33 +08:00
..
bat_algo.h
bat_iv_ogm.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-01-11 23:55:43 -05:00
bitarray.c
bitarray.h
bridge_loop_avoidance.c	batman-adv: Avoid recursive call_rcu for batadv_bla_claim	2016-01-16 22:48:29 +08:00
bridge_loop_avoidance.h	batman-adv: purge bridge loop avoidance when its disabled	2016-01-09 20:56:00 +08:00
debugfs.c
debugfs.h
distributed-arp-table.c
distributed-arp-table.h
fragmentation.c	batman-adv: Use chain pointer when purging fragments	2015-12-16 15:17:09 +08:00
fragmentation.h
gateway_client.c	batman-adv: Only put gw_node list reference when removed	2016-02-16 17:52:25 +08:00
gateway_client.h
gateway_common.c	batman-adv: Add function to convert string to batadv throughput	2016-01-09 20:56:00 +08:00
gateway_common.h
hard-interface.c	batman-adv: Avoid endless loop in bat-on-bat netdevice check	2016-02-16 22:16:33 +08:00
hard-interface.h	batman-adv: Drop immediate batadv_hard_iface free function	2016-01-16 22:49:51 +08:00
hash.c
hash.h
icmp_socket.c
icmp_socket.h
Kconfig
main.c	batman-adv: Less checks in batadv_tvlv_unicast_send()	2016-01-09 20:56:00 +08:00
main.h	batman-adv: increase BLA wait periods to 6	2016-01-09 20:56:00 +08:00
Makefile
multicast.c	batman-adv: fix lockdep splat when doing mcast_free	2016-01-13 19:26:25 +08:00
multicast.h
network-coding.c	batman-adv: Avoid recursive call_rcu for batadv_nc_node	2016-01-16 22:48:41 +08:00
network-coding.h
originator.c	batman-adv: Drop immediate orig_node free function	2016-01-16 22:50:00 +08:00
originator.h	batman-adv: Drop immediate orig_node free function	2016-01-16 22:50:00 +08:00
packet.h	batman-adv: remove leftovers of unused BATADV_PRIMARIES_FIRST_HOP flag	2016-01-09 20:56:00 +08:00
routing.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-12-17 22:08:28 -05:00
routing.h
send.c	batman-adv: Delete unnecessary checks before the function call "kfree_skb"	2016-01-09 20:56:00 +08:00
send.h
soft-interface.c
soft-interface.h
sysfs.c	batman-adv: only call post function if something changed	2016-01-09 20:56:00 +08:00
sysfs.h
translation-table.c	batman-adv: Only put orig_node_vlan list reference when removed	2016-02-16 17:52:26 +08:00
translation-table.h
types.h	batman-adv: Add kerneldoc for batadv_neigh_node::refcount	2016-01-09 20:56:00 +08:00