====================================================== WARNING: possible circular locking dependency detected 4.20.0+ #7 Not tainted ------------------------------------------------------ swapper/0/0 is trying to acquire lock: 00000000e9348b87 (nr_list_lock){+.-.}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000e9348b87 (nr_list_lock){+.-.}, at: nr_remove_socket net/netrom/af_netrom.c:96 [inline] 00000000e9348b87 (nr_list_lock){+.-.}, at: nr_destroy_socket+0x96/0x6e0 net/netrom/af_netrom.c:264 but task is already holding lock: 00000000a1ea9165 (slock-AF_NETROM){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] 00000000a1ea9165 (slock-AF_NETROM){+.-.}, at: nr_destroy_timer+0x32/0x90 net/netrom/af_netrom.c:247 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (slock-AF_NETROM){+.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] nr_find_listener net/netrom/af_netrom.c:156 [inline] nr_rx_frame+0x60c/0x1d50 net/netrom/af_netrom.c:955 nr_loopback_timer+0x7b/0x170 net/netrom/nr_loopback.c:62 call_timer_fn+0x254/0x900 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers+0x6fc/0xd50 kernel/time/timer.c:1681 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 arch_local_irq_restore arch/x86/include/asm/paravirt.h:766 [inline] kmem_cache_free+0xab/0x260 mm/slab.c:3748 anon_vma_chain_free mm/rmap.c:135 [inline] unlink_anon_vmas+0x3ab/0xa50 mm/rmap.c:402 free_pgtables+0x1af/0x2f0 mm/memory.c:393 exit_mmap+0x2e3/0x5d0 mm/mmap.c:3141 __mmput kernel/fork.c:1051 [inline] mmput+0x240/0x640 kernel/fork.c:1072 exec_mmap fs/exec.c:1043 [inline] flush_old_exec+0xb6d/0x21a0 fs/exec.c:1276 load_elf_binary+0xa76/0x53c0 fs/binfmt_elf.c:869 search_binary_handler fs/exec.c:1653 [inline] search_binary_handler+0x17f/0x570 fs/exec.c:1631 exec_binprm fs/exec.c:1695 [inline] __do_execve_file.isra.0+0x1452/0x2510 fs/exec.c:1819 do_execveat_common fs/exec.c:1866 [inline] do_execve fs/exec.c:1883 [inline] __do_sys_execve fs/exec.c:1964 [inline] __se_sys_execve fs/exec.c:1959 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1959 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (nr_list_lock){+.-.}: lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] nr_remove_socket net/netrom/af_netrom.c:96 [inline] nr_destroy_socket+0x96/0x6e0 net/netrom/af_netrom.c:264 nr_destroy_timer+0x42/0x90 net/netrom/af_netrom.c:249 call_timer_fn+0x254/0x900 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers+0x6fc/0xd50 kernel/time/timer.c:1681 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 rest_init+0x245/0x37b init/main.c:443 arch_call_rest_init+0xe/0x1b start_kernel+0x882/0x8bd init/main.c:741 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(slock-AF_NETROM); lock(nr_list_lock); lock(slock-AF_NETROM); lock(nr_list_lock); *** DEADLOCK *** 2 locks held by swapper/0/0: #0: 00000000c16231ac ((&sk->sk_timer)#2){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:171 [inline] #0: 00000000c16231ac ((&sk->sk_timer)#2){+.-.}, at: call_timer_fn+0x1b4/0x900 kernel/time/timer.c:1315 #1: 00000000a1ea9165 (slock-AF_NETROM){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] #1: 00000000a1ea9165 (slock-AF_NETROM){+.-.}, at: nr_destroy_timer+0x32/0x90 net/netrom/af_netrom.c:247 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1224 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2350 [inline] __lock_acquire+0x3014/0x4a30 kernel/locking/lockdep.c:3338 lock_acquire+0x1db/0x570 kernel/locking/lockdep.c:3841 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] nr_remove_socket net/netrom/af_netrom.c:96 [inline] nr_destroy_socket+0x96/0x6e0 net/netrom/af_netrom.c:264 nr_destroy_timer+0x42/0x90 net/netrom/af_netrom.c:249 call_timer_fn+0x254/0x900 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers+0x6fc/0xd50 kernel/time/timer.c:1681 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:58 Code: ff ff ff 48 89 c7 48 89 45 d8 e8 c9 3d d2 f9 48 8b 45 d8 e9 ce fe ff ff 48 89 df e8 b8 3d d2 f9 eb 82 90 90 90 90 90 90 fb f4 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90 RSP: 0018:ffffffff89807c60 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13249e9 RBX: 1ffffffff1300f8f RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8987b73c RBP: ffffffff89807d20 R08: ffffffff8987aec0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff89807cf8 R14: 0000000000000000 R15: ffffffff89924f38 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:555 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x386/0x5d0 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 rest_init+0x245/0x37b init/main.c:443 arch_call_rest_init+0xe/0x1b start_kernel+0x882/0x8bd init/main.c:741 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' SELinux: unrecognized netlink message: protocol=6 nlmsg_type=8704 sclass=netlink_xfrm_socket pig=25086 comm=syz-executor3 kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (00000000ae337ee9): kobject_uevent_env kobject: 'loop3' (00000000ae337ee9): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (00000000f371d6a0): kobject_uevent_env kobject: 'loop2' (00000000f371d6a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' QAT: Invalid ioctl QAT: Invalid ioctl kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (00000000f371d6a0): kobject_uevent_env kobject: 'loop2' (00000000f371d6a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000ae337ee9): kobject_uevent_env kobject: 'loop3' (00000000ae337ee9): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env audit: type=1400 audit(1546543843.524:118): avc: denied { block_suspend } for pid=25200 comm="syz-executor5" capability=36 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=capability2 permissive=1 kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop3' (00000000ae337ee9): kobject_uevent_env kobject: 'loop3' (00000000ae337ee9): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop2' (00000000f371d6a0): kobject_uevent_env kobject: 'loop2' (00000000f371d6a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' Debayer B: ================= START STATUS ================= kobject: 'loop5' (0000000073d4768c): kobject_uevent_env Debayer B: ================== END STATUS ================== kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop5' (0000000073d4768c): kobject_uevent_env kobject: 'loop5' (0000000073d4768c): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (00000000ad8c2aee): kobject_uevent_env kobject: 'loop1' (00000000ad8c2aee): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop2' (00000000f371d6a0): kobject_uevent_env kobject: 'loop2' (00000000f371d6a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000ae337ee9): kobject_uevent_env kobject: 'loop3' (00000000ae337ee9): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop0' (000000002ff2e7e2): kobject_uevent_env kobject: 'loop0' (000000002ff2e7e2): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (00000000f371d6a0): kobject_uevent_env kobject: 'loop2' (00000000f371d6a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (00000000ae337ee9): kobject_uevent_env kobject: 'loop3' (00000000ae337ee9): fill_kobj_path: path = '/devices/virtual/block/loop3'