rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=a3d/1/0x4000000000000000 softirq=66940/66940 fqs=11 (t=10500 jiffies g=124097 q=208) rcu: rcu_preempt kthread starved for 10477 jiffies! g124097 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:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3605 Comm: syz-fuzzer Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd6c/0x54a0 kernel/locking/lockdep.c:4897 Code: 41 89 85 58 0a 00 00 0f 87 18 0b 00 00 3b 05 9b d7 10 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 89 d7 10 0e e9 bd 00 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 0f RSP: 0018:ffffc90000007c58 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffffffff8bba0548 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002 R13: ffff88807c6a21c0 R14: 0000000000000002 R15: 0000000000000001 FS: 000000c0001d6c90(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15a4b9a000 CR3: 000000001ce63000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x147/0x470 kernel/time/timekeeping.c:829 clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:qlist_free_all+0x67/0x110 mm/kasan/quarantine.c:160 Code: 28 bd 81 48 c1 e8 03 42 c6 04 28 fb e8 d2 7a ff ff 48 85 db 75 52 9c 58 f6 c4 02 0f 85 a4 00 00 00 48 85 db 74 01 fb 48 85 ed <74> 73 48 89 ee 4d 85 e4 4c 89 e7 74 38 48 63 87 80 00 00 00 48 8b RSP: 0018:ffffc90001f27838 EFLAGS: 00000286 RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1ff7ec6 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88801fbd6000 R08: 0000000000000001 R09: ffffffff8ff77abf R10: 0000000000000001 R11: 000000000000003f R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90001f27880 R15: ffffea0000000000 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 ____kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc+0xba/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:269 [inline] kmem_cache_alloc_node_trace+0x208/0x5b0 mm/slab.c:3619 __do_kmalloc_node mm/slab.c:3639 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb_fclone include/linux/skbuff.h:1176 [inline] tcp_stream_alloc_skb+0x66/0x910 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xaba/0x3050 net/ipv4/tcp.c:1281 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1440 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x289/0x3c0 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x1ee/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4b12db Code: fb ff eb bd e8 46 96 fb ff e9 61 ff ff ff cc e8 fb 61 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 RSP: 002b:000000c0003712e8 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000c000020800 RCX: 00000000004b12db RDX: 000000000000001a RSI: 000000c00000a200 RDI: 0000000000000006 RBP: 000000c000371338 R08: 000000c000371301 R09: 0000000000000004 R10: 000000c00000a1e0 R11: 0000000000000212 R12: 000000000000011e R13: 000000c0004d0000 R14: 0000000000000007 R15: 0000000000007702 NMI backtrace for cpu 1 CPU: 1 PID: 21975 Comm: syz-executor.2 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 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+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lockdep_copy_map include/linux/lockdep.h:35 [inline] RIP: 0010:call_timer_fn+0xf6/0x6b0 kernel/time/timer.c:1411 Code: c0 84 c1 0f 85 ae 05 00 00 48 c7 44 24 40 00 00 00 00 49 8b 44 24 28 48 c7 44 24 48 00 00 00 00 48 89 44 24 38 49 8b 44 24 40 <48> 89 44 24 50 49 8b 44 24 48 48 89 44 24 58 e8 46 13 11 00 45 31 RSP: 0018:ffffc90000fd8d38 EFLAGS: 00000246 RAX: ffffffff8ab08100 RBX: 0000000000000100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8165d101 RDI: ffff88803735fc38 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8ff77abf R10: 0000000000000001 R11: 0000000000000000 R12: ffff88803735fc10 R13: 1ffff920001fb1a8 R14: ffffffff87481bb0 R15: ffff8880b9d28280 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_cmp2+0x77/0x80 kernel/kcov.c:256 Code: f0 72 27 41 0f b7 fb 41 0f b7 c9 48 83 c2 01 48 c7 44 30 e0 02 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 <5b> c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 89 RSP: 0018:ffffc90002b776a8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc90002b77770 RCX: ffff8880196ac1c0 RDX: 0000000000000000 RSI: ffff8880196ac1c0 RDI: 0000000000000003 RBP: ffff8880809fa020 R08: 0000000000000000 R09: 000000000000c8e9 R10: ffffffff88629ff5 R11: 000000000000c8e9 R12: 000000000000c8e9 R13: 000000000000c8e9 R14: ffffffff8d5e7800 R15: 0000000000000001 sctp_v4_cmp_addr net/sctp/protocol.c:302 [inline] sctp_v4_cmp_addr+0xf5/0x1d0 net/sctp/protocol.c:297 sctp_bind_addr_state+0x103/0x1d0 net/sctp/bind_addr.c:407 sctp_copy_local_addr_list+0x1fe/0x4f0 net/sctp/protocol.c:162 sctp_copy_one_addr net/sctp/bind_addr.c:460 [inline] sctp_bind_addr_copy+0x299/0x460 net/sctp/bind_addr.c:68 sctp_connect_new_asoc+0x1cd/0x770 net/sctp/socket.c:1092 sctp_sendmsg_new_asoc net/sctp/socket.c:1690 [inline] sctp_sendmsg+0x13bc/0x1d30 net/sctp/socket.c:2000 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7ccc6f2e99 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:00007f7ccb068168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f7ccc805f60 RCX: 00007f7ccc6f2e99 RDX: 00000000000000fc RSI: 00000000200006c0 RDI: 0000000000000004 RBP: 00007f7ccc74d031 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7d33172f R14: 00007f7ccb068300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 41 89 85 58 0a 00 00 mov %eax,0xa58(%r13) 7: 0f 87 18 0b 00 00 ja 0xb25 d: 3b 05 9b d7 10 0e cmp 0xe10d79b(%rip),%eax # 0xe10d7ae 13: 41 be 01 00 00 00 mov $0x1,%r14d 19: 0f 86 c8 00 00 00 jbe 0xe7 1f: 89 05 89 d7 10 0e mov %eax,0xe10d789(%rip) # 0xe10d7ae 25: e9 bd 00 00 00 jmpq 0xe7 * 2a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 31: fc ff df 34: 48 89 da mov %rbx,%rdx 37: 48 c1 ea 03 shr $0x3,%rdx 3b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 3f: 0f .byte 0xf