rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=d55/1/0x4000000000000000 softirq=69916/69917 fqs=7 (t=10500 jiffies g=124413 q=150) rcu: rcu_preempt kthread timer wakeup didn't happen for 10475 jiffies! g124413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=36994 rcu: rcu_preempt kthread starved for 10476 jiffies! g124413 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28944 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 28109 Comm: syz-executor.1 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_preemption_disabled+0x1b/0x170 lib/smp_processor_id.c:16 Code: 0f 1f 44 00 00 0f 0b e9 23 ff ff ff cc cc cc 41 56 41 55 49 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 dd b6 bd 76 <65> 8b 1d 4e 11 be 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 RSP: 0018:ffffc90000fd8f58 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff89abf980 RDI: ffffffff8a0491e0 RBP: ffffffff8a0491e0 R08: 0000000000000000 R09: ffffffff8d90f657 R10: fffffbfff1b21eca R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff89abf980 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007ff238a4d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3392a000 CR3: 000000002c149000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:433 [inline] lock_is_held_type+0x63/0x140 kernel/locking/lockdep.c:5679 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_local_timer_exit arch/x86/include/asm/trace/irq_vectors.h:41 [inline] __sysvec_apic_timer_interrupt+0x332/0x530 arch/x86/kernel/apic/apic.c:1104 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:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:200 Code: 45 00 5d be 03 00 00 00 e9 36 db 63 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 39 8b 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9 RSP: 0018:ffffc9000f41f1b8 EFLAGS: 00000202 RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffff888078d80000 RDX: 0000000000000000 RSI: ffff888078d80000 RDI: 0000000000000003 RBP: ffff888083cc1aa8 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8223f4b2 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888070577000 R14: ffff888017366b88 R15: ffff88814af5a000 jbd2_journal_get_write_access+0xfb/0x190 fs/jbd2/transaction.c:1226 __ext4_journal_get_write_access+0x1ba/0x540 fs/ext4/ext4_jbd2.c:233 ext4_reserve_inode_write+0x241/0x3c0 fs/ext4/inode.c:5716 __ext4_mark_inode_dirty+0x17b/0x8d0 fs/ext4/inode.c:5882 ext4_dirty_inode+0xd4/0x110 fs/ext4/inode.c:5919 __mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2399 mark_inode_dirty include/linux/fs.h:2451 [inline] generic_write_end+0x31b/0x500 fs/buffer.c:2202 ext4_da_write_end+0x1c2/0x990 fs/ext4/inode.c:3059 generic_perform_write+0x2c6/0x510 mm/filemap.c:3767 ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681 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+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: 0033:0x7ff23a0d7e99 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:00007ff238a4d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007ff23a1eaf60 RCX: 00007ff23a0d7e99 RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000000006 RBP: 00007ff23a132031 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7154aedf R14: 00007ff238a4d300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 28090 Comm: syz-executor.4 Not tainted 5.16.0-rc4-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: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:lock_release+0x3f1/0x720 kernel/locking/lockdep.c:5645 Code: 7e 83 f8 01 0f 85 8d 01 00 00 9c 58 f6 c4 02 0f 85 78 01 00 00 48 f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c5 48 c7 45 00 00 00 00 00 c7 45 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000f55f180 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 67fc13014b334417 RCX: ffffc9000f55f1d0 RDX: 1ffff1100656d162 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff92001eabe32 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000003 R14: ffff888032b68b18 R15: ffff888032b680c0 up_read+0x12/0x20 kernel/locking/rwsem.c:1565 ext4_da_map_blocks fs/ext4/inode.c:1793 [inline] ext4_da_get_block_prep+0xcc2/0x11f0 fs/ext4/inode.c:1827 ext4_block_write_begin+0x539/0x1140 fs/ext4/inode.c:1078 ext4_da_write_begin+0x3eb/0xad0 fs/ext4/inode.c:2966 generic_perform_write+0x205/0x510 mm/filemap.c:3756 ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681 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+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: 0033:0x7f8977f25e99 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:00007f897689b168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f8978038f60 RCX: 00007f8977f25e99 RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000000005 RBP: 00007f8977f80031 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe0daea5af R14: 00007f897689b300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 5: 0f 0b ud2 7: e9 23 ff ff ff jmpq 0xffffff2f c: cc int3 d: cc int3 e: cc int3 f: 41 56 push %r14 11: 41 55 push %r13 13: 49 89 f5 mov %rsi,%r13 16: 41 54 push %r12 18: 55 push %rbp 19: 48 89 fd mov %rdi,%rbp 1c: 53 push %rbx 1d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 22: 65 44 8b 25 dd b6 bd mov %gs:0x76bdb6dd(%rip),%r12d # 0x76bdb707 29: 76 * 2a: 65 8b 1d 4e 11 be 76 mov %gs:0x76be114e(%rip),%ebx # 0x76be117f <-- trapping instruction 31: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx 37: 31 ff xor %edi,%edi 39: 89 de mov %ebx,%esi 3b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)