rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10496 ticks this GP) idle=99f/1/0x4000000000000000 softirq=35233/35233 fqs=0 (t=10501 jiffies g=61221 q=527) rcu: rcu_preempt kthread starved for 10502 jiffies! g61221 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:28688 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15803 Comm: syz-executor.4 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110 Code: c7 00 08 16 8f e8 68 65 8b 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 86 1f 2e 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48 RSP: 0018:ffffc90000007410 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b562a80 RCX: 0000000000000020 RDX: 1ffffffff16ac552 RSI: 00000000000000ce RDI: 0000000000000380 RBP: ffff8880b9c27300 R08: 000000000000003f R09: 0000000000000000 R10: ffffffff816a4257 R11: 0000000000000000 R12: 00000000000000ce R13: 0000000000000020 R14: 0000000000000001 R15: ffff8880b9c2a400 FS: 00007fc6b3290700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f255dae0558 CR3: 000000005a82d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x4d/0x80 arch/x86/kernel/apic/apic.c:469 clockevents_program_event+0x254/0x370 kernel/time/clockevents.c:334 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 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:debug_lockdep_rcu_enabled+0x25/0x30 kernel/rcu/update.c:280 Code: cc cc cc cc cc 8b 05 ea 08 4d 04 85 c0 74 21 8b 05 1c 3c 4d 04 85 c0 74 17 65 48 8b 04 25 40 70 02 00 8b 80 5c 0a 00 00 85 c0 <0f> 94 c0 0f b6 c0 c3 cc cc cc cc 41 54 55 48 c7 c5 50 aa 03 00 53 RSP: 0018:ffffc90000007610 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880579c1400 RCX: 0000000000000100 RDX: ffff8880732c8000 RSI: ffffffff87e8b5f0 RDI: ffff8880579c0e08 RBP: dffffc0000000000 R08: 00000000fffffffd R09: 0000000000000000 R10: ffffffff87e8b51b R11: 0000000000000000 R12: ffff8880579c0e54 R13: ffffc90000007908 R14: 0000000000000000 R15: ffff8880579c0ea0 rcu_read_lock_held_common kernel/rcu/update.c:104 [inline] rcu_read_lock_held+0x5/0x40 kernel/rcu/update.c:309 __find_rr_leaf+0x27e/0xd20 net/ipv6/route.c:791 find_rr_leaf net/ipv6/route.c:847 [inline] rt6_select net/ipv6/route.c:891 [inline] fib6_table_lookup+0x649/0xa20 net/ipv6/route.c:2185 ip6_pol_route+0x1c5/0x11d0 net/ipv6/route.c:2221 pol_lookup_func include/net/ip6_fib.h:580 [inline] fib6_rule_lookup+0x111/0x6f0 net/ipv6/fib6_rules.c:115 ip6_route_input_lookup net/ipv6/route.c:2291 [inline] ip6_route_input+0x63c/0xbc0 net/ipv6/route.c:2587 ip6_rcv_finish_core.constprop.0.isra.0+0x168/0x570 net/ipv6/ip6_input.c:63 ip6_rcv_finish net/ipv6/ip6_input.c:74 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x229/0x3c0 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5462 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5576 process_backlog+0x2a5/0x6c0 net/core/dev.c:6452 __napi_poll+0xaf/0x440 net/core/dev.c:7020 napi_poll net/core/dev.c:7087 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7174 __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:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:121 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:435 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3c4/0xb40 kernel/locking/qspinlock.c:508 Code: 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 41 83 ec 01 0f 84 72 04 00 00 <41> 0f b6 45 00 38 d8 7f 08 84 c0 0f 85 91 05 00 00 0f b6 45 00 84 RSP: 0018:ffffc900183be8b0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1ffff11029604438 RDX: 0000000000000001 RSI: dffffc0000000000 RDI: ffff88814b0221c2 RBP: ffff88814b0221c0 R08: 0000000000000001 R09: ffff88814b0221c3 R10: ffffed1029604438 R11: 0000000000000000 R12: 0000000000001b77 R13: ffffed1029604438 R14: 0000000000000001 R15: ffff8880b9c3a880 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:349 [inline] ext4_lock_group+0x1e5/0x240 fs/ext4/ext4.h:3519 ext4_mb_find_by_goal+0x2ca/0xd60 fs/ext4/mballoc.c:2219 ext4_mb_regular_allocator+0x237/0x3870 fs/ext4/mballoc.c:2654 ext4_mb_new_blocks+0x24d2/0x51f0 fs/ext4/mballoc.c:5586 ext4_ext_map_blocks+0x1fa3/0x5fd0 fs/ext4/extents.c:4285 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637 ext4_iomap_alloc fs/ext4/inode.c:3365 [inline] ext4_iomap_begin+0x4a1/0x7f0 fs/ext4/inode.c:3415 iomap_iter+0x454/0x11b0 fs/iomap/iter.c:74 __iomap_dio_rw+0x6b2/0x1a10 fs/iomap/direct-io.c:588 iomap_dio_rw+0x38/0x90 fs/iomap/direct-io.c:679 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xe1b/0x14e0 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_iter_write+0x70/0xa0 fs/read_write.c:892 iter_file_splice_write+0x723/0xc70 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 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: 0033:0x7fc6b5d1aae9 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:00007fc6b3290188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fc6b5e2df60 RCX: 00007fc6b5d1aae9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007fc6b5d74f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000401ffc023 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc6b6361b2f R14: 00007fc6b3290300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 15804 Comm: syz-executor.2 Not tainted 5.16.0-rc3-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:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 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:pv_wait_node kernel/locking/qspinlock_paravirt.h:301 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x5c4/0xb40 kernel/locking/qspinlock.c:473 Code: 32 84 c0 75 23 41 0f b6 14 24 4c 89 e9 83 e1 07 38 ca 7f 08 84 d2 0f 85 ed 03 00 00 0f b6 53 14 84 d2 0f 85 9e 00 00 00 f3 90 <83> e8 01 0f 84 93 00 00 00 0f b6 16 84 d2 74 09 80 fa 03 0f 8e 96 RSP: 0018:ffffc900183cea88 EFLAGS: 00000206 RAX: 000000000000617e RBX: ffff8880b9c3a880 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffed10173a7511 RDI: ffff8880b9d3a894 RBP: ffff8880b9d3a894 R08: 0000000000000001 R09: ffff8880b9d3a894 R10: ffffed10173a7512 R11: 0000000000000000 R12: ffffed1017387512 R13: ffff8880b9c3a894 R14: dffffc0000000000 R15: ffff8880b9d3a880 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:349 [inline] ext4_lock_group+0x1e5/0x240 fs/ext4/ext4.h:3519 ext4_mb_mark_diskspace_used+0x551/0x1240 fs/ext4/mballoc.c:3837 ext4_mb_new_blocks+0xd2e/0x51f0 fs/ext4/mballoc.c:5604 ext4_ext_map_blocks+0x1fa3/0x5fd0 fs/ext4/extents.c:4285 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:637 ext4_iomap_alloc fs/ext4/inode.c:3365 [inline] ext4_iomap_begin+0x4a1/0x7f0 fs/ext4/inode.c:3415 iomap_iter+0x454/0x11b0 fs/iomap/iter.c:74 __iomap_dio_rw+0x6b2/0x1a10 fs/iomap/direct-io.c:588 iomap_dio_rw+0x38/0x90 fs/iomap/direct-io.c:679 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xe1b/0x14e0 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_iter_write+0x70/0xa0 fs/read_write.c:892 iter_file_splice_write+0x723/0xc70 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 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: 0033:0x7f4d9d442ae9 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:00007f4d9a9b8188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f4d9d555f60 RCX: 00007f4d9d442ae9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007f4d9d49cf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000401ffc023 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4d9da89b2f R14: 00007f4d9a9b8300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c7 00 08 16 8f e8 movl $0xe88f1608,(%rax) 6: 68 65 8b 00 eb pushq $0xffffffffeb008b65 b: b0 66 mov $0x66,%al d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 12: be 01 00 00 00 mov $0x1,%esi 17: e9 86 1f 2e 00 jmpq 0x2e1fa2 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: 89 ff mov %edi,%edi 24: 89 b7 00 c0 5f ff mov %esi,-0xa04000(%rdi) * 2a: c3 retq <-- trapping instruction 2b: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 53 push %rbx 3d: 89 fb mov %edi,%ebx 3f: 48 rex.W