rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=3fa/1/0x4000000000000000 softirq=36341/36341 fqs=2 (t=10501 jiffies g=39985 q=477) rcu: rcu_preempt kthread starved for 10498 jiffies! g39985 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:29176 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x148/0x250 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1940 [inline] rcu_gp_kthread+0xbbe/0x1d70 kernel/rcu/tree.c:2113 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 1 CPU: 1 PID: 15933 Comm: syz-executor.2 Not tainted 5.11.0-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+0x107/0x163 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+0x1f4/0x230 kernel/rcu/tree_stall.h:337 print_cpu_stall kernel/rcu/tree_stall.h:569 [inline] check_cpu_stall kernel/rcu/tree_stall.h:643 [inline] rcu_pending kernel/rcu/tree.c:3751 [inline] rcu_sched_clock_irq.cold+0x48e/0xedf kernel/rcu/tree.c:2580 update_process_times+0x16d/0x200 kernel/time/timer.c:1782 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:1519 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline] sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:lock_is_held_type+0xe8/0x120 kernel/locking/lockdep.c:5486 Code: 03 44 39 f0 41 0f 94 c5 48 c7 c7 a0 aa 4b 89 e8 0e 0d 00 00 b8 ff ff ff ff 65 0f c1 05 21 20 08 77 83 f8 01 75 1b ff 34 24 9d <48> 83 c4 08 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb RSP: 0000:ffffc90000db0560 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000104 RDI: 0000000000000000 RBP: ffffffff8b373ce0 R08: 0000000000000000 R09: ffffffff8d038a8f R10: fffffbfff1a07151 R11: 0000000000000001 R12: ffff888011af8000 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888011af89b0 lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x5d2/0x720 kernel/locking/lockdep.c:5413 rcu_lock_acquire include/linux/rcupdate.h:259 [inline] rcu_read_lock include/linux/rcupdate.h:648 [inline] is_bpf_text_address+0x36/0x160 kernel/bpf/core.c:700 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:318 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:313 arch_stack_walk+0x93/0xe0 arch/x86/kernel/stacktrace.c:26 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:356 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362 kasan_slab_free include/linux/kasan.h:192 [inline] slab_free_hook mm/slub.c:1547 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1580 slab_free mm/slub.c:3143 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3159 kfree_skbmem+0x166/0x1b0 net/core/skbuff.c:657 sk_wmem_free_skb include/net/sock.h:1552 [inline] tcp_rtx_queue_purge net/ipv4/tcp.c:2857 [inline] tcp_write_queue_purge+0x444/0x14a0 net/ipv4/tcp.c:2870 tcp_write_err net/ipv4/tcp_timer.c:73 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:276 [inline] tcp_retransmit_timer+0x21ba/0x33a0 net/ipv4/tcp_timer.c:512 tcp_write_timer_handler+0x5bb/0xaf0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744 __do_softirq+0x29b/0x9f6 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu kernel/softirq.c:420 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199 Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 1e 77 5c f8 48 89 ef e8 c6 2b 5d f8 e8 41 49 7c f8 fb bf 01 00 00 00 06 33 51 f8 65 8b 05 ff aa 05 77 85 c0 74 02 5d c3 e8 6b 00 04 RSP: 0000:ffffc900017cfe20 EFLAGS: 00000202 RAX: 0000000000000c43 RBX: 0000000000000005 RCX: 1ffffffff1a06a11 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffff8880b9f34c40 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff81788e28 R11: 0000000000000001 R12: ffff8880b9f34c40 R13: ffff888011af8000 R14: ffffffff8ae66168 R15: ffff888011af8000 __schedule+0x18cf/0x21a0 kernel/sched/core.c:5084 schedule+0xcf/0x270 kernel/sched/core.c:5157 exit_to_user_mode_loop kernel/entry/common.c:162 [inline] exit_to_user_mode_prepare+0x115/0x250 kernel/entry/common.c:201 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:315 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629 RIP: 0033:0x465b09 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f591951d188 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000042000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffffcae5caf R14: 00007f591951d300 R15: 0000000000022000