2 locks held by dhclient/7265: #0: ffff8880738c2120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1604 [inline] #0: ffff8880738c2120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2f/0xc00 net/packet/af_packet.c:3125 #1: ffffffff8bf7cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8bf7cee8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x620 kernel/rcu/tree_exp.h:836 ============================================= rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=d6e/1/0x4000000000000000 softirq=82656/82657 fqs=0 (t=18183 jiffies g=140673 q=3141) NMI backtrace for cpu 0 CPU: 0 PID: 7254 Comm: kworker/u4:3 Not tainted 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x222/0x2a7 kernel/rcu/tree_stall.h:341 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline] check_cpu_stall kernel/rcu/tree_stall.h:697 [inline] rcu_pending kernel/rcu/tree.c:3830 [inline] rcu_sched_clock_irq.cold+0x4f7/0x11dd kernel/rcu/tree.c:2650 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191 Code: 74 24 10 e8 da 0b 54 f8 48 89 ef e8 02 c2 54 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 f3 8f 48 f8 65 8b 05 9c 5a fc 76 85 c0 74 0a 5b 5d c3 e8 50 4b RSP: 0018:ffffc90000007b10 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1f5e972 RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff88801b134000 R08: 0000000000000001 R09: ffffffff8fa9a98f R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801bbc2440 R13: ffff88804b909600 R14: dffffc0000000000 R15: ffff888084348f00 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] dummy_timer+0x12f1/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1985 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745 __run_timers kernel/time/timer.c:1726 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:49 [inline] RIP: 0010:unwind_next_frame+0x14fd/0x1ce0 arch/x86/kernel/unwind_orc.c:604 Code: 00 0f 85 92 05 00 00 49 39 ec 49 8b 46 10 0f 87 d7 f9 ff ff 48 39 e8 0f 86 ce f9 ff ff 48 8d 55 08 48 39 d0 0f 93 c1 49 39 d4 <0f> 92 c0 84 c1 0f 84 b6 f9 ff ff 48 39 6c 24 18 0f 82 ab f9 ff ff RSP: 0018:ffffc90016b9f948 EFLAGS: 00000287 RAX: ffffc90016ba0000 RBX: 1ffff92002d73f31 RCX: 1ffff92002d73f01 RDX: ffffc90016b9fb10 RSI: ffffc90016b9faf8 RDI: ffffc90016b9fa80 RBP: ffffc90016b9fb08 R08: ffffffff8e3ba2ce R09: 0000000000000001 R10: fffff52002d73f59 R11: 0000000000084087 R12: ffffc90016b98000 R13: ffffc90016b9faa5 R14: ffffc90016b9fa70 R15: ffffc90016b9faa4 __unwind_start+0x51b/0x800 arch/x86/kernel/unwind_orc.c:699 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0x5c/0xe0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kmem_cache_free+0x8a/0x740 mm/slub.c:3177 putname+0xe1/0x120 fs/namei.c:259 kernel_execve+0x38d/0x460 fs/exec.c:1977 call_usermodehelper_exec_async+0x2de/0x580 kernel/umh.c:110 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294