rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=e15/1/0x4000000000000000 softirq=64546/64547 fqs=0 (t=10501 jiffies g=98445 q=99) rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g98445 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=56454 rcu: rcu_preempt kthread starved for 10504 jiffies! g98445 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:28592 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: 4016 Comm: syz-executor.4 Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5380 [inline] RIP: 0010:lock_is_held_type+0x9f/0x140 kernel/locking/lockdep.c:5680 Code: 05 06 37 bd 76 85 c0 7f 12 e9 8a 00 00 00 83 c3 01 41 3b 9c 24 58 0a 00 00 7d 7d 48 63 c3 48 89 ee 48 8d 04 80 4d 8d 7c c5 00 <4c> 89 ff e8 99 fe ff ff 85 c0 74 d8 41 83 fe ff 41 bd 01 00 00 00 RSP: 0018:ffffc90000fd8d78 EFLAGS: 00000093 RAX: 0000000000000005 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bb81260 RDI: ffff88804bb0abe0 RBP: ffffffff8bb81260 R08: 0000000000000000 R09: ffffffff8d911997 R10: fffffbfff1b22332 R11: 0000000000000000 R12: ffff88804bb0a180 R13: ffff88804bb0abe0 R14: 00000000ffffffff R15: ffff88804bb0ac08 FS: 00007f88e6e96700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d22b000 CR3: 00000000577cf000 CR4: 00000000003506e0 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5608 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] ktime_get_update_offsets_now+0x82/0x5c0 kernel/time/timekeeping.c:2296 hrtimer_update_base kernel/time/hrtimer.c:631 [inline] hrtimer_interrupt+0x3ad/0x790 kernel/time/hrtimer.c:1843 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_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: 8d a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000b107248 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92001620e4b RCX: ffffffff815b9a1f RDX: 1ffff1100976157b RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ff7ba5f R10: fffffbfff1fef74b R11: 000000000000003f R12: 0000000000000000 R13: 0000000000000000 R14: ffff88804fe9eab0 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] create_empty_buffers+0xbc/0x800 fs/buffer.c:1569 ext4_block_write_begin+0xd1d/0x1140 fs/ext4/inode.c:1060 ext4_da_write_begin+0x3eb/0xad0 fs/ext4/inode.c:2966 generic_perform_write+0x205/0x510 mm/filemap.c:3754 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: 0033:0x7f88e8520e99 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:00007f88e6e96168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f88e8633f60 RCX: 00007f88e8520e99 RDX: 0000000000000000 RSI: 000000000000000f RDI: 0000000000000006 RBP: 00007f88e857aff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffef449adcf R14: 00007f88e6e96300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 4013 Comm: syz-executor.5 Not tainted 5.16.0-rc6-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:orc_find arch/x86/kernel/unwind_orc.c:164 [inline] RIP: 0010:unwind_next_frame+0x279/0x1ce0 arch/x86/kernel/unwind_orc.c:443 Code: 24 30 48 89 74 24 28 44 89 5c 24 20 e8 80 2d 89 00 48 8b 54 24 30 48 8b 74 24 28 44 8b 5c 24 20 8b 0c 95 20 03 aa 8e 8d 56 01 <48> b8 00 00 00 00 00 fc ff df 48 8d 3c 95 20 03 aa 8e 49 89 f8 49 RSP: 0018:ffffc9000b0d6e50 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 1ffff9200161add2 RCX: 0000000000033d2e RDX: 000000000000d8ec RSI: 000000000000d8eb RDI: ffffffff8ead66cc RBP: 0000000000000001 R08: ffffffff8b9fa420 R09: 0000000000000001 R10: fffff5200161adf0 R11: 000000000008808a R12: ffffc9000b0d6f70 R13: ffffc9000b0d6f5d R14: ffffc9000b0d6f28 R15: ffffffff81d8eb07 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 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+0x85/0xb0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc mm/slab.c:3323 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3507 kmem_cache_zalloc include/linux/slab.h:714 [inline] alloc_buffer_head+0x20/0x140 fs/buffer.c:3309 alloc_page_buffers+0x268/0x5f0 fs/buffer.c:832 create_empty_buffers+0x2c/0x800 fs/buffer.c:1560 ext4_block_write_begin+0xd1d/0x1140 fs/ext4/inode.c:1060 ext4_da_write_begin+0x3eb/0xad0 fs/ext4/inode.c:2966 generic_perform_write+0x205/0x510 mm/filemap.c:3754 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: 0033:0x7fb27a109e99 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:00007fb278a7f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fb27a21cf60 RCX: 00007fb27a109e99 RDX: 0000000000000000 RSI: 000000000000000f RDI: 0000000000000006 RBP: 00007fb27a163ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcd084755f R14: 00007fb278a7f300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 05 06 37 bd 76 add $0x76bd3706,%eax 5: 85 c0 test %eax,%eax 7: 7f 12 jg 0x1b 9: e9 8a 00 00 00 jmpq 0x98 e: 83 c3 01 add $0x1,%ebx 11: 41 3b 9c 24 58 0a 00 cmp 0xa58(%r12),%ebx 18: 00 19: 7d 7d jge 0x98 1b: 48 63 c3 movslq %ebx,%rax 1e: 48 89 ee mov %rbp,%rsi 21: 48 8d 04 80 lea (%rax,%rax,4),%rax 25: 4d 8d 7c c5 00 lea 0x0(%r13,%rax,8),%r15 * 2a: 4c 89 ff mov %r15,%rdi <-- trapping instruction 2d: e8 99 fe ff ff callq 0xfffffecb 32: 85 c0 test %eax,%eax 34: 74 d8 je 0xe 36: 41 83 fe ff cmp $0xffffffff,%r14d 3a: 41 bd 01 00 00 00 mov $0x1,%r13d