INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=11176, c=11175, q=125) All QSes seen, last rcu_preempt kthread activity 10502 (4294988501-4294977999), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.3 R running task 27888 20558 6357 0x00000008 Call Trace: sched_show_task kernel/sched/core.c:5168 [inline] sched_show_task.cold+0x2e3/0x347 kernel/sched/core.c:5143 print_other_cpu_stall kernel/rcu/tree.c:1501 [inline] check_cpu_stall kernel/rcu/tree.c:1616 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0xd3f/0xdaa kernel/rcu/tree.c:2792 update_process_times+0x29/0x60 kernel/time/timer.c:1590 tick_sched_handle+0x7d/0x150 kernel/time/tick-sched.c:165 tick_sched_timer+0x3e/0x120 kernel/time/tick-sched.c:1223 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x25c/0xbb0 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:27 [inline] RIP: 0010:__orc_find+0x6f/0xf0 arch/x86/kernel/unwind_orc.c:49 RSP: 0018:ffff8880aea07300 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff113a767 RBX: ffffffff889d3b38 RCX: ffffffff8129e74e RDX: 0000000000000000 RSI: ffffffff88e9ab3a RDI: ffffffff889d3b34 RBP: ffffffff889d3b34 R08: ffffffff88e9ab64 R09: ffff8880aea07ff8 R10: ffff8880aea0742d R11: 0000000000058071 R12: ffffffff889d3b3c R13: ffffffff889d3b34 R14: ffffffff889d3b34 R15: dffffc0000000000 orc_find arch/x86/kernel/unwind_orc.c:121 [inline] unwind_next_frame+0x5de/0x17a0 arch/x86/kernel/unwind_orc.c:348 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137 __alloc_skb+0xca/0x4c0 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] sctp_packet_transmit+0x30c/0x2d70 net/sctp/output.c:580 sctp_outq_flush+0xc54/0x2dd0 net/sctp/outqueue.c:1187 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1787 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline] sctp_do_sm+0x419/0x4a90 net/sctp/sm_sideeffect.c:1150 sctp_generate_heartbeat_event+0x1da/0x3f0 net/sctp/sm_sideeffect.c:391 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0x52a/0x1390 kernel/time/timer.c:1649 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:790 [inline] RIP: 0010:flush_tlb_mm_range+0x27e/0x300 arch/x86/mm/tlb.c:705 RSP: 0018:ffff8881fd24f410 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0fa2cd3 RBX: ffff888044712040 RCX: 1ffff1103fc145ae RDX: dffffc0000000000 RSI: ffff8881fe0a2d50 RDI: ffff8881fe0a2cfc RBP: 0000000020018000 R08: ffff888044712040 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1103fa49e83 R13: 0000000000000000 R14: 0000000020017000 R15: 0000000000000000 flush_tlb_page arch/x86/include/asm/tlbflush.h:573 [inline] ptep_clear_flush+0xd6/0x100 mm/pgtable-generic.c:87 wp_page_copy+0x78f/0x1300 mm/memory.c:2539 do_wp_page+0x244/0x11d0 mm/memory.c:2784 handle_pte_fault mm/memory.c:4005 [inline] __handle_mm_fault+0x1c0e/0x3280 mm/memory.c:4113 handle_mm_fault+0x288/0x7a0 mm/memory.c:4150 __do_page_fault+0x4bc/0xb40 arch/x86/mm/fault.c:1442 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1122 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:181 RSP: 0018:ffff8881fd24f918 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 0000000000001000 RCX: 0000000000000040 RDX: 0000000000001000 RSI: ffff888040650fc0 RDI: 0000000020017000 RBP: 0000000020016040 R08: ffffed10080ca200 R09: 0000000000000000 R10: ffffed10080ca1ff R11: ffff888040650fff R12: ffff888040650000 R13: 00007ffffffff000 R14: 0000000020017040 R15: ffff8881fd24fd88 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:112 [inline] copyout+0x99/0xc0 lib/iov_iter.c:137 copy_page_to_iter_iovec lib/iov_iter.c:206 [inline] copy_page_to_iter+0x32a/0xc80 lib/iov_iter.c:723 skb_copy_datagram_iter+0x401/0x910 net/core/datagram.c:452 skb_copy_datagram_msg include/linux/skbuff.h:3307 [inline] unix_stream_read_actor+0x78/0xb0 net/unix/af_unix.c:2475 unix_stream_read_generic+0x752/0x1920 net/unix/af_unix.c:2396 unix_stream_recvmsg+0x9b/0xc0 net/unix/af_unix.c:2491 sock_recvmsg_nosec net/socket.c:819 [inline] sock_recvmsg net/socket.c:826 [inline] sock_recvmsg+0xc0/0x100 net/socket.c:822 SYSC_recvfrom+0x18c/0x290 net/socket.c:1815 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c889 RSP: 002b:00007ff5cf20dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007ff5cf20e6d4 RCX: 000000000045c889 RDX: 571e03255a93f039 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 000000000076c040 R08: 0000000020000100 R09: 0000000000930000 R10: 0000000000100100 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000898 R14: 00000000004cb4dd R15: 000000000076c04c rcu_preempt kthread starved for 10502 jiffies! g11176 c11175 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 rcu_preempt R running task 29920 8 2 0x80000000 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x43c/0xe40 kernel/time/timer.c:1746 rcu_gp_kthread+0xb8e/0x1ce0 kernel/rcu/tree.c:2255 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404