rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=60f/1/0x4000000000000000 softirq=194780/194781 fqs=4838 (t=10502 jiffies g=353061 q=21608) NMI backtrace for cpu 1 CPU: 1 PID: 1250 Comm: syz-executor.5 Not tainted 5.16.0-rc2-next-20211125-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:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2617 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:fib_rule_match net/core/fib_rules.c:265 [inline] RIP: 0010:fib_rules_lookup+0x13a/0xc20 net/core/fib_rules.c:302 Code: 00 00 00 00 fc ff df 49 89 c7 48 89 44 24 30 49 c1 ef 03 49 01 ef e8 f5 49 35 fa 48 8d 7b 10 48 89 f8 48 c1 e8 03 0f b6 04 28 <84> c0 74 08 3c 03 0f 8e 7f 09 00 00 44 8b 6b 10 31 ff 44 89 ee e8 RSP: 0018:ffffc90000dd0118 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff888075d31400 RCX: 0000000000000100 RDX: ffff888153e39d40 RSI: ffffffff87429aeb RDI: ffff888075d31410 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87429b92 R11: 0000000000000000 R12: ffffc90000dd0670 R13: 0000000000000000 R14: 0000000000000001 R15: fffff520001ba0cf fib6_rule_lookup+0x4ba/0x6f0 net/ipv6/fib6_rules.c:107 ip6_route_output_flags_noref+0x2e2/0x380 net/ipv6/route.c:2627 ip6_route_output_flags+0x72/0x320 net/ipv6/route.c:2640 ip6_dst_lookup_tail+0xa13/0x1620 net/ipv6/ip6_output.c:1097 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1200 sctp_v6_get_dst+0x107e/0x1d60 net/sctp/ipv6.c:385 sctp_transport_route+0x125/0x350 net/sctp/transport.c:458 sctp_packet_config+0xa01/0xe50 net/sctp/output.c:103 sctp_packet_singleton+0x162/0x360 net/sctp/outqueue.c:771 sctp_outq_flush_ctrl.constprop.0+0x5dc/0xab0 net/sctp/outqueue.c:908 sctp_outq_flush net/sctp/outqueue.c:1202 [inline] sctp_outq_uncork+0x10b/0x200 net/sctp/outqueue.c:758 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1812 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1195 [inline] sctp_do_sm+0x745/0x4ee0 net/sctp/sm_sideeffect.c:1166 sctp_generate_timeout_event+0x1bb/0x3d0 net/sctp/sm_sideeffect.c:295 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 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:deref_stack_reg+0xa/0x150 arch/x86/kernel/unwind_orc.c:351 Code: 24 e8 ba 7b 8e 00 48 8b 14 24 e9 48 ff ff ff 48 89 0c 24 e8 a8 7b 8e 00 48 8b 0c 24 eb 9d 66 90 48 b8 00 00 00 00 00 fc ff df <41> 55 41 54 49 89 fc 55 48 89 f5 53 48 89 d3 48 89 fa 48 c1 ea 03 RSP: 0018:ffffc9000cfc7740 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff920019f8ef1 RCX: ffffffff8e0c3ed9 RDX: ffffc9000cfc78b8 RSI: ffffc9000cfc7868 RDI: ffffc9000cfc7870 RBP: 0000000000000001 R08: ffffffff8e0c3ed4 R09: 0000000000000001 R10: fffff520019f8f19 R11: 000000000008808a R12: ffffc9000cfc78b8 R13: ffffc9000cfc78a5 R14: ffffc9000cfc7870 R15: ffffffff8e0c3ed8 unwind_next_frame+0xcdc/0x1ce0 arch/x86/kernel/unwind_orc.c:534 __unwind_start+0x51b/0x800 arch/x86/kernel/unwind_orc.c:712 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x5c/0xe0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:724 [inline] class_dir_create_and_add drivers/base/core.c:2939 [inline] get_device_parent+0x314/0x590 drivers/base/core.c:3003 device_add+0x2a8/0x1ee0 drivers/base/core.c:3315 cdev_device_add+0x12a/0x210 fs/char_dev.c:549 uif_init drivers/mtd/ubi/build.c:466 [inline] ubi_attach_mtd_dev+0x1642/0x32c0 drivers/mtd/ubi/build.c:985 ctrl_cdev_ioctl+0x2f0/0x390 drivers/mtd/ubi/cdev.c:1043 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x7fa656268ae9 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:00007fa65519c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa65637c0f0 RCX: 00007fa656268ae9 RDX: 0000000020006000 RSI: 0000000040186f40 RDI: 0000000000000005 RBP: 00007fa6562c2ff7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffecc2e8aff R14: 00007fa65519c300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 7 bytes skipped: 0: 49 89 c7 mov %rax,%r15 3: 48 89 44 24 30 mov %rax,0x30(%rsp) 8: 49 c1 ef 03 shr $0x3,%r15 c: 49 01 ef add %rbp,%r15 f: e8 f5 49 35 fa callq 0xfa354a09 14: 48 8d 7b 10 lea 0x10(%rbx),%rdi 18: 48 89 f8 mov %rdi,%rax 1b: 48 c1 e8 03 shr $0x3,%rax 1f: 0f b6 04 28 movzbl (%rax,%rbp,1),%eax * 23: 84 c0 test %al,%al <-- trapping instruction 25: 74 08 je 0x2f 27: 3c 03 cmp $0x3,%al 29: 0f 8e 7f 09 00 00 jle 0x9ae 2f: 44 8b 6b 10 mov 0x10(%rbx),%r13d 33: 31 ff xor %edi,%edi 35: 44 89 ee mov %r13d,%esi 38: e8 .byte 0xe8