cgroup: fork rejected by pids controller in =============================== [ INFO: suspicious RCU usage. ] 4.7.0-rc3-syzkaller #0 Not tainted ------------------------------- include/linux/cgroup.h:434 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by syz-executor.3/19992: IPv6: ADDRCONF(NETDEV_CHANGE): nr5: link becomes ready #0: (&cgroup_threadgroup_rwsem){++++++}, at: [] cgroup_threadgroup_change_begin include/linux/cgroup-defs.h:532 [inline] #0: (&cgroup_threadgroup_rwsem){++++++}, at: [] threadgroup_change_begin include/linux/sched.h:2956 [inline] #0: (&cgroup_threadgroup_rwsem){++++++}, at: [] copy_process.part.7+0xef8/0x5ba0 kernel/fork.c:1409 stack backtrace: CPU: 0 PID: 19992 Comm: syz-executor.3 Not tainted 4.7.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 ffff8801c0787af8 ffffffff82c97d22 ffff8801b7d3e740 0000000000000000 0000000000000001 ffffffff85eb7200 ffffffff86f29e40 ffff8801c0787b28 ffffffff81436889 ffff8801b7d3e740 ffff8800ab00ad40 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0x136/0x1d4 lib/dump_stack.c:51 [] lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4440 [] task_css include/linux/cgroup.h:434 [inline] [] task_cgroup include/linux/cgroup.h:479 [inline] [] pids_can_fork+0x384/0x3d0 kernel/cgroup_pids.c:232 [] cgroup_can_fork+0xe9/0x200 kernel/cgroup.c:5848 [] copy_process.part.7+0x3fa5/0x5ba0 kernel/fork.c:1567 [] copy_process kernel/fork.c:1310 [inline] [] _do_fork+0x148/0xbb0 kernel/fork.c:1762 [] SYSC_clone kernel/fork.c:1871 [inline] [] SyS_clone+0x14/0x20 kernel/fork.c:1865 [] do_syscall_64+0x1cc/0x5d0 arch/x86/entry/common.c:350 [] entry_SYSCALL64_slow_path+0x25/0x25 /system.slice/ssh.service batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves IPVS: Creating netns size=2720 id=8 IPVS: ftp: loaded support on port[0] = 21 chnl_net:caif_netlink_parms(): no params data found bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_1 entered promiscuous mode bond0: Enslaving bond_slave_0 as an active interface with an up link bond0: Enslaving bond_slave_1 as an active interface with an up link batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready device veth0_vlan entered promiscuous mode device veth1_vlan entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready device veth0_macvtap entered promiscuous mode device veth1_macvtap entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_0 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready