rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17038 (detected by 0, t=10503 jiffies, g=617853, q=1848) task:syz-executor.3 state:R running task stack:25216 pid:17038 ppid: 6564 flags:0x0000400e Call Trace: sched_show_task kernel/sched/core.c:8545 [inline] sched_show_task+0x433/0x5b0 kernel/sched/core.c:8519 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:227 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:567 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq+0x1fa5/0x2200 kernel/rcu/tree.c:2599 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:1421 __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+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:sctp_bind_addr_state+0xc6/0x1d0 net/sctp/bind_addr.c:405 Code: 89 44 24 08 49 c1 ef 03 49 8d 04 2f 48 89 04 24 e8 ff df 1a f9 48 8d 7b 3d 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 0f b6 04 28 <38> d0 7f 08 84 c0 0f 85 ba 00 00 00 44 0f b6 7b 3d 31 ff 44 89 fe RSP: 0018:ffffc900013ef8b8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff88802c9c4000 RCX: ffffc90010052000 RDX: 0000000000000005 RSI: ffffffff885b2b31 RDI: ffff88802c9c403d RBP: dffffc0000000000 R08: 0000000000000000 R09: 000000000000000a R10: ffffffff885b2b8f R11: 000000000000000a R12: ffffc900013ef948 R13: ffff8880760a4098 R14: ffffffff8d3d44a0 R15: 0000000000000000 sctp_copy_local_addr_list+0x1fe/0x4f0 net/sctp/protocol.c:163 sctp_copy_one_addr net/sctp/bind_addr.c:460 [inline] sctp_bind_addr_copy+0xde/0x460 net/sctp/bind_addr.c:56 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:817 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 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: 0033:0x7f51c66608d9 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:00007f51c3bd7188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f51c6764f60 RCX: 00007f51c66608d9 RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000005 RBP: 00007f51c66bacb4 R08: 0000000020000240 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3aa2faaf R14: 00007f51c3bd7300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 89 44 24 08 mov %eax,0x8(%rsp) 4: 49 c1 ef 03 shr $0x3,%r15 8: 49 8d 04 2f lea (%r15,%rbp,1),%rax c: 48 89 04 24 mov %rax,(%rsp) 10: e8 ff df 1a f9 callq 0xf91ae014 15: 48 8d 7b 3d lea 0x3d(%rbx),%rdi 19: 48 89 f8 mov %rdi,%rax 1c: 48 89 fa mov %rdi,%rdx 1f: 48 c1 e8 03 shr $0x3,%rax 23: 83 e2 07 and $0x7,%edx 26: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax * 2a: 38 d0 cmp %dl,%al <-- trapping instruction 2c: 7f 08 jg 0x36 2e: 84 c0 test %al,%al 30: 0f 85 ba 00 00 00 jne 0xf0 36: 44 0f b6 7b 3d movzbl 0x3d(%rbx),%r15d 3b: 31 ff xor %edi,%edi 3d: 44 89 fe mov %r15d,%esi