IPVS: ftp: loaded support on port[0] = 21 ====================================================== WARNING: possible circular locking dependency detected 4.14.213-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:2/34 is trying to acquire lock: (&qdisc_rx_lock){+.-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (&qdisc_rx_lock){+.-.}, at: [] red_adaptative_timer+0x72/0x570 net/sched/sch_red.c:233 but task is already holding lock: (((&q->adapt_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] (((&q->adapt_timer))){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1270 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (((&q->adapt_timer))){+.-.}: del_timer_sync+0xaf/0x240 kernel/time/timer.c:1236 red_destroy+0x15/0x50 net/sched/sch_red.c:154 qdisc_destroy+0x13c/0x310 net/sched/sch_generic.c:726 red_change+0x4a4/0xf80 net/sched/sch_red.c:205 qdisc_change net/sched/sch_api.c:1144 [inline] tc_modify_qdisc+0xd4e/0x1250 net/sched/sch_api.c:1410 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&qdisc_rx_lock){+.-.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] red_adaptative_timer+0x72/0x570 net/sched/sch_red.c:233 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x254/0xa1d kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 preempt_count_equals kernel/sched/core.c:5972 [inline] ___might_sleep+0x6c/0x2b0 kernel/sched/core.c:6005 inet_twsk_purge+0x9a/0x5a0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:145 cleanup_net+0x3b3/0x840 net/core/net_namespace.c:484 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(((&q->adapt_timer))); lock(&qdisc_rx_lock); lock(((&q->adapt_timer))); lock(&qdisc_rx_lock); *** DEADLOCK *** 4 locks held by kworker/u4:2/34: #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x110/0x840 net/core/net_namespace.c:450 #3: (((&q->adapt_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #3: (((&q->adapt_timer))){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1270 stack backtrace: CPU: 0 PID: 34 Comm: kworker/u4:2 Not tainted 4.14.213-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] red_adaptative_timer+0x72/0x570 net/sched/sch_red.c:233 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x254/0xa1d kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:preempt_count_equals kernel/sched/core.c:5972 [inline] RIP: 0010:___might_sleep+0x6c/0x2b0 kernel/sched/core.c:6005 RSP: 0018:ffff8880b56c7bc8 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 1ffff11016ad70a8 RSI: 00000000ffffffff RDI: ffff8880b56b8540 RBP: ffffffff885c9540 R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000000000 R11: ffff8880b56b81c0 R12: 000000000000010c R13: 0000000000000000 R14: ffff8880b56b81c0 R15: dffffc0000000000 inet_twsk_purge+0x9a/0x5a0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0xf9/0x150 net/core/net_namespace.c:145 cleanup_net+0x3b3/0x840 net/core/net_namespace.c:484 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21