rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 1, t=10502 jiffies, g=569793, q=586) rcu: All QSes seen, last rcu_preempt kthread activity 10491 (4295292534-4295282043), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10491 jiffies! g569793 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28880 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 23026 Comm: syz-executor.4 Not tainted 5.14.0-rc7-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:105 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_check_gp_kthread_starvation.cold+0x1d1/0x1d6 kernel/rcu/tree_stall.h:479 print_other_cpu_stall kernel/rcu/tree_stall.h:584 [inline] check_cpu_stall kernel/rcu/tree_stall.h:709 [inline] rcu_pending kernel/rcu/tree.c:3922 [inline] rcu_sched_clock_irq+0x2001/0x20c0 kernel/rcu/tree.c:2641 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:1537 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__orc_find+0x2/0xf0 arch/x86/kernel/unwind_orc.c:37 Code: e8 43 b6 bc 02 e9 60 fb ff ff e8 29 ce 88 00 e9 cf fb ff ff cc cc cc cc 48 8b 07 c3 66 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 <89> d0 41 56 41 55 41 54 4c 8d 64 87 fc 55 53 48 83 ec 10 85 d2 0f RSP: 0018:ffffc90000dc0688 EFLAGS: 00000216 RAX: 0000000000142e54 RBX: 1ffff920001b80db RCX: ffffffff87115b04 RDX: 000000000000000c RSI: ffffffff8e5ac808 RDI: ffffffff8dc6e080 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8e5ac808 R10: fffff520001b80f9 R11: 0000000000086088 R12: ffffc90000dc07b8 R13: ffffc90000dc07a5 R14: ffffc90000dc0770 R15: ffffffff87115b04 orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x32a/0x1ce0 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x83/0xb0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2959 [inline] kmem_cache_alloc_node+0x266/0x3e0 mm/slub.c:2995 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 skb_copy+0x137/0x2f0 net/core/skbuff.c:1585 mac80211_hwsim_tx_frame_no_nl.isra.0+0xb17/0x1330 drivers/net/wireless/mac80211_hwsim.c:1565 mac80211_hwsim_tx_frame+0x1ee/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1784 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:85 [inline] RIP: 0010:lock_is_held_type+0x14/0x140 kernel/locking/lockdep.c:5661 Code: ac bd ff 0f 0b 8b 44 24 04 eb bd 66 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 41 55 41 bd ff ff ff ff 41 54 55 53 48 83 ec 08 <8b> 0d 42 39 3d 04 85 c9 0f 84 d7 00 00 00 65 8b 05 47 26 d2 76 85 RSP: 0018:ffffc900016ff350 EFLAGS: 00000286 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff815b2401 RDX: 1ffffffff1730a26 RSI: 00000000ffffffff RDI: ffffffff8b97c1c0 RBP: 1ffff920002dfe76 R08: 0000000000000000 R09: ffffffff8d6cda57 R10: fffffbfff1ad9b4a R11: 0000000000000000 R12: 0000000000000001 R13: 00000000ffffffff R14: ffffc900016ff6e8 R15: ffff8880564afa80 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5636 rcu_lock_release include/linux/rcupdate.h:272 [inline] rcu_read_unlock include/linux/rcupdate.h:720 [inline] fib_lookup.constprop.0+0x225/0x460 include/net/ip_fib.h:393 ip_route_output_key_hash_rcu+0xf30/0x2d00 net/ipv4/route.c:2737 ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2627 __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2858 ip_route_output_key include/net/route.h:142 [inline] sctp_v4_get_dst+0x3bd/0x11d0 net/sctp/protocol.c:449 sctp_transport_pmtu+0x293/0x5d0 net/sctp/transport.c:240 sctp_transport_route+0x15b/0x350 net/sctp/transport.c:464 sctp_assoc_add_peer+0x6e6/0x14b0 net/sctp/associola.c:665 sctp_connect_add_peer+0x21f/0x2c0 net/sctp/socket.c:1151 sctp_sendmsg_new_asoc net/sctp/socket.c:1737 [inline] sctp_sendmsg+0x1751/0x1d30 net/sctp/socket.c:2000 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2403 ___sys_sendmsg+0xf3/0x170 net/socket.c:2457 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486 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: 0033:0x4665f9 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:00007f0bb1537188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056c1a8 RCX: 00000000004665f9 RDX: 00000000000000fc RSI: 00000000200006c0 RDI: 0000000000000008 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c1a8 R13: 00007ffd99f693ff R14: 00007f0bb1537300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: e8 43 b6 bc 02 callq 0x2bcb648 5: e9 60 fb ff ff jmpq 0xfffffb6a a: e8 29 ce 88 00 callq 0x88ce38 f: e9 cf fb ff ff jmpq 0xfffffbe3 14: cc int3 15: cc int3 16: cc int3 17: cc int3 18: 48 8b 07 mov (%rdi),%rax 1b: c3 retq 1c: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 23: 00 00 00 00 27: 90 nop 28: 41 57 push %r15 * 2a: 89 d0 mov %edx,%eax <-- trapping instruction 2c: 41 56 push %r14 2e: 41 55 push %r13 30: 41 54 push %r12 32: 4c 8d 64 87 fc lea -0x4(%rdi,%rax,4),%r12 37: 55 push %rbp 38: 53 push %rbx 39: 48 83 ec 10 sub $0x10,%rsp 3d: 85 d2 test %edx,%edx 3f: 0f .byte 0xf