rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10210 ticks this GP) idle=ab9/1/0x4000000000000000 softirq=137806/137811 fqs=10 (t=10500 jiffies g=211945 q=426) rcu: rcu_preempt kthread starved for 10456 jiffies! g211945 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:29152 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 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 0 CPU: 0 PID: 4417 Comm: syz-executor.1 Not tainted 5.14.0-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+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x98/0x746 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+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:__sanitizer_cov_trace_cmp8+0xc/0x70 kernel/kcov.c:263 Code: e8 48 c7 44 38 e0 07 00 00 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 <48> 89 f1 65 48 8b 34 25 40 f0 01 00 e8 c3 f1 ff ff 84 c0 74 48 48 RSP: 0018:ffffc90000007b90 EFLAGS: 00000203 RAX: 0000000000000000 RBX: ffff88808b198c80 RCX: 0000000000000100 RDX: ffff88807b6c8000 RSI: 000000008b198c80 RDI: 0000000000000003 RBP: ffff88810b198c80 R08: ffff88810b198c80 R09: 0000000000000000 R10: ffffffff81349e5e R11: 000000000000003f R12: 000000008b198c80 R13: ffffffff81bcacfa R14: 0000000000000000 R15: 0000000000000000 __phys_addr+0x4e/0x140 arch/x86/mm/physaddr.c:28 virt_to_head_page include/linux/mm.h:900 [inline] ____kasan_slab_free mm/kasan/common.c:344 [inline] __kasan_slab_free+0x38/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kmem_cache_free+0x8a/0x5b0 mm/slub.c:3229 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699 __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:911 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:905 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1785 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:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 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:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__schedule+0x1/0x26f0 kernel/sched/core.c:6166 Code: 5d 41 5c c3 e8 10 e0 86 f8 eb d9 e8 09 e0 86 f8 e9 4b ff ff ff e8 9f df 86 f8 e9 02 ff ff ff e8 b5 df 86 f8 e9 6c ff ff ff 55 <48> 89 e5 41 57 48 8d 85 78 ff ff ff 41 56 48 c1 e8 03 41 55 41 54 RSP: 0018:ffffc9000a4cf648 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff88807b6c8000 RCX: 1ffffffff1addb1d RDX: 0000000000000000 RSI: ffffffff817c49b1 RDI: 0000000000000001 RBP: ffffed100f6d9000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817c4998 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode+0x7/0x40 kernel/kcov.c:163 Code: 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 63 dd 46 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 65 8b 05 09 d7 8b 7e <89> c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b RSP: 0018:ffffc9000a4cf728 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffff88807b6c8000 RDX: 0000000000040000 RSI: ffff88807b6c8000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81cdd7a7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000009 R14: 0000000000000009 R15: ffff88807b6c8000 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 do_select+0x1137/0x16a0 fs/select.c:583 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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:00007fccb0b14188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd43b7c20f R14: 00007fccb0b14300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 4417 Comm: syz-executor.1 Not tainted 5.14.0-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+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 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+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:__sanitizer_cov_trace_cmp8+0xc/0x70 kernel/kcov.c:263 Code: e8 48 c7 44 38 e0 07 00 00 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 <48> 89 f1 65 48 8b 34 25 40 f0 01 00 e8 c3 f1 ff ff 84 c0 74 48 48 RSP: 0018:ffffc90000007b90 EFLAGS: 00000203 RAX: 0000000000000000 RBX: ffff88808b198c80 RCX: 0000000000000100 RDX: ffff88807b6c8000 RSI: 000000008b198c80 RDI: 0000000000000003 RBP: ffff88810b198c80 R08: ffff88810b198c80 R09: 0000000000000000 R10: ffffffff81349e5e R11: 000000000000003f R12: 000000008b198c80 R13: ffffffff81bcacfa R14: 0000000000000000 R15: 0000000000000000 __phys_addr+0x4e/0x140 arch/x86/mm/physaddr.c:28 virt_to_head_page include/linux/mm.h:900 [inline] ____kasan_slab_free mm/kasan/common.c:344 [inline] __kasan_slab_free+0x38/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kmem_cache_free+0x8a/0x5b0 mm/slub.c:3229 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699 __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:911 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:905 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1785 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:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 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:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__schedule+0x1/0x26f0 kernel/sched/core.c:6166 Code: 5d 41 5c c3 e8 10 e0 86 f8 eb d9 e8 09 e0 86 f8 e9 4b ff ff ff e8 9f df 86 f8 e9 02 ff ff ff e8 b5 df 86 f8 e9 6c ff ff ff 55 <48> 89 e5 41 57 48 8d 85 78 ff ff ff 41 56 48 c1 e8 03 41 55 41 54 RSP: 0018:ffffc9000a4cf648 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff88807b6c8000 RCX: 1ffffffff1addb1d RDX: 0000000000000000 RSI: ffffffff817c49b1 RDI: 0000000000000001 RBP: ffffed100f6d9000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817c4998 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode+0x7/0x40 kernel/kcov.c:163 Code: 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 63 dd 46 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 65 8b 05 09 d7 8b 7e <89> c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b RSP: 0018:ffffc9000a4cf728 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffff88807b6c8000 RDX: 0000000000040000 RSI: ffff88807b6c8000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81cdd7a7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000009 R14: 0000000000000009 R15: ffff88807b6c8000 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 do_select+0x1137/0x16a0 fs/select.c:583 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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:00007fccb0b14188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd43b7c20f R14: 00007fccb0b14300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: e8 48 c7 44 38 callq 0x3844c74d 5: e0 07 loopne 0xe 7: 00 00 add %al,(%rax) 9: 00 48 89 add %cl,-0x77(%rax) c: 4c 38 f0 rex.WR cmp %r14b,%al f: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) 14: 48 89 10 mov %rdx,(%rax) 17: c3 retq 18: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 1e: 49 89 f8 mov %rdi,%r8 21: bf 03 00 00 00 mov $0x3,%edi 26: 4c 8b 14 24 mov (%rsp),%r10 * 2a: 48 89 f1 mov %rsi,%rcx <-- trapping instruction 2d: 65 48 8b 34 25 40 f0 mov %gs:0x1f040,%rsi 34: 01 00 36: e8 c3 f1 ff ff callq 0xfffff1fe 3b: 84 c0 test %al,%al 3d: 74 48 je 0x87 3f: 48 rex.W