rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=8e3/1/0x4000000000000000 softirq=21860/21864 fqs=1 (t=10501 jiffies g=28085 q=12) rcu: rcu_preempt kthread starved for 10499 jiffies! g28085 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:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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: 7965 Comm: syz-executor.5 Not tainted 5.16.0-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: 00 00 be 01 00 00 00 e9 46 67 2d 00 66 0f 1f 44 00 00 b8 01 00 00 00 c3 cc cc cc cc 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:ffffc90000007eb8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b588a80 RCX: 0000000000000020 RDX: 1ffffffff16b1152 RSI: 0000000000000087 RDI: 0000000000000380 RBP: ffff8880b9c272c0 R08: 000000000000003f R09: 0000000000000000 R10: ffffffff816a1967 R11: 0000000000000001 R12: 0000000000000087 R13: 0000000000000020 R14: 0000000000000000 R15: ffff8880b9c2a600 FS: 00007f290cf28700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ee35000 CR3: 0000000021327000 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+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:queued_write_lock_slowpath+0x137/0x2c0 kernel/locking/qrwlock.c:78 Code: 00 00 00 00 fc ff df 49 01 c7 41 83 c6 03 41 0f b6 07 41 38 c6 7c 08 84 c0 0f 85 3e 01 00 00 8b 03 3d 00 01 00 00 74 19 f3 90 <41> 0f b6 07 41 38 c6 7c ec 84 c0 74 e8 48 89 df e8 74 58 61 00 eb RSP: 0018:ffffc90002c871d0 EFLAGS: 00000206 RAX: 0000000000000300 RBX: ffff88814acd40c0 RCX: ffffffff815cf0ff RDX: ffffed102959a819 RSI: 0000000000000004 RDI: ffff88814acd40c0 RBP: 1ffff92000590e3b R08: 0000000000000001 R09: ffff88814acd40c3 R10: ffffed102959a818 R11: 0000000000000001 R12: ffff88814acd40c4 R13: 00000000000000ff R14: 0000000000000003 R15: ffffed102959a818 queued_write_lock include/asm-generic/qrwlock.h:97 [inline] do_raw_write_lock+0x1ce/0x280 kernel/locking/spinlock_debug.c:210 jbd2_log_start_commit+0x1f/0x40 fs/jbd2/journal.c:525 jbd2_journal_stop+0x502/0xf20 fs/jbd2/transaction.c:1913 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:127 ext4_dirty_inode+0xe8/0x110 fs/ext4/inode.c:5903 __mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2409 mark_inode_dirty include/linux/fs.h:2379 [inline] generic_write_end+0x31b/0x500 fs/buffer.c:2203 ext4_da_write_end+0x1c2/0x990 fs/ext4/inode.c:3042 generic_perform_write+0x2c6/0x510 mm/filemap.c:3698 ext4_buffered_write_iter+0x1a2/0x390 fs/ext4/file.c:268 ext4_file_write_iter+0x423/0x14d0 fs/ext4/file.c:677 call_write_iter include/linux/fs.h:2086 [inline] do_iter_readv_writev+0x47a/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+0x6fa/0xc10 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: 0033:0x7f290e5b2fe9 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:00007f290cf28168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f290e6c5f60 RCX: 00007f290e5b2fe9 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000005 RBP: 00007f290e60d08d R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe5b4b9aff R14: 00007f290cf28300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 7958 Comm: syz-executor.2 Not tainted 5.16.0-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: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+0x5c/0x759 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+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:start_this_handle+0x388/0x1380 fs/jbd2/transaction.c:409 Code: 89 e6 e8 9b e1 51 ff 45 85 e4 0f 85 d6 01 00 00 e8 6d df 51 ff 48 8b 44 24 18 80 38 00 0f 85 ad 0d 00 00 4c 8b a3 98 01 00 00 <4d> 85 e4 0f 84 51 01 00 00 e8 4a df 51 ff 8b 54 24 3c 48 89 df 8b RSP: 0018:ffffc90003b87268 EFLAGS: 00000246 RAX: ffffed102959a833 RBX: ffff88814acd4000 RCX: ffffc9000353d000 RDX: 0000000000040000 RSI: ffffffff8225a973 RDI: 0000000000000003 RBP: ffff88814acd4100 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8225a965 R11: 0000000000000000 R12: ffff88802d4a7b00 R13: 0000000000000000 R14: ffff88803e50f6ac R15: dffffc0000000000 jbd2__journal_start+0x399/0x930 fs/jbd2/transaction.c:525 __ext4_journal_start_sb+0x227/0x4a0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5899 __mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2409 mark_inode_dirty include/linux/fs.h:2379 [inline] generic_write_end+0x31b/0x500 fs/buffer.c:2203 ext4_da_write_end+0x1c2/0x990 fs/ext4/inode.c:3042 generic_perform_write+0x2c6/0x510 mm/filemap.c:3698 ext4_buffered_write_iter+0x1a2/0x390 fs/ext4/file.c:268 ext4_file_write_iter+0x423/0x14d0 fs/ext4/file.c:677 call_write_iter include/linux/fs.h:2086 [inline] do_iter_readv_writev+0x47a/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+0x6fa/0xc10 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: 0033:0x7fb20d7f6fe9 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:00007fb20c16c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fb20d909f60 RCX: 00007fb20d7f6fe9 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000005 RBP: 00007fb20d85108d R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffccdd2020f R14: 00007fb20c16c300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: be 01 00 00 00 mov $0x1,%esi 7: e9 46 67 2d 00 jmpq 0x2d6752 c: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 12: b8 01 00 00 00 mov $0x1,%eax 17: c3 retq 18: cc int3 19: cc int3 1a: cc int3 1b: cc int3 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