rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=789/1/0x4000000000000000 softirq=20063/20063 fqs=0 (t=10501 jiffies g=28477 q=139) rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g28477 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=12352 rcu: rcu_preempt kthread starved for 10504 jiffies! g28477 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28936 pid: 14 ppid: 2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 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 </TASK> rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 8251 Comm: syz-executor.4 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __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_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:3878 [inline] rcu_sched_clock_irq.cold+0x57/0x759 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 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:memcg_slab_pre_alloc_hook mm/slab.h:287 [inline] RIP: 0010:slab_pre_alloc_hook mm/slab.h:497 [inline] RIP: 0010:slab_alloc mm/slab.c:3306 [inline] RIP: 0010:kmem_cache_alloc+0x9b/0x560 mm/slab.c:3507 Code: 75 0a f6 43 23 04 0f 84 97 00 00 00 e8 fe 90 06 00 48 85 c0 48 89 c5 0f 84 86 00 00 00 8b 53 14 44 89 e6 48 89 c7 48 83 c2 08 <e8> a0 a5 06 00 85 c0 74 72 e8 a7 7c a5 ff 31 d2 45 31 c9 45 31 c0 RSP: 0018:ffffc900113df290 EFLAGS: 00000216 RAX: ffff888075287d00 RBX: ffff888011dc9f00 RCX: ffffc900113df1e8 RDX: 00000000000000f0 RSI: 0000000000408d40 RDI: ffff888075287d00 RBP: ffff888075287d00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000408d40 R13: 0000000000408d40 R14: 0000000000000400 R15: 00000000000000a8 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: 0033:0x7f4f2b53ae99 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:00007f4f29eb0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f4f2b64df60 RCX: 00007f4f2b53ae99 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 0000000000000005 RBP: 00007f4f2b594ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4187a21f R14: 00007f4f29eb0300 R15: 0000000000022000 </TASK> NMI backtrace for cpu 0 CPU: 0 PID: 8251 Comm: syz-executor.4 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __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+0x5c/0x759 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 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:memcg_slab_pre_alloc_hook mm/slab.h:287 [inline] RIP: 0010:slab_pre_alloc_hook mm/slab.h:497 [inline] RIP: 0010:slab_alloc mm/slab.c:3306 [inline] RIP: 0010:kmem_cache_alloc+0x9b/0x560 mm/slab.c:3507 Code: 75 0a f6 43 23 04 0f 84 97 00 00 00 e8 fe 90 06 00 48 85 c0 48 89 c5 0f 84 86 00 00 00 8b 53 14 44 89 e6 48 89 c7 48 83 c2 08 <e8> a0 a5 06 00 85 c0 74 72 e8 a7 7c a5 ff 31 d2 45 31 c9 45 31 c0 RSP: 0018:ffffc900113df290 EFLAGS: 00000216 RAX: ffff888075287d00 RBX: ffff888011dc9f00 RCX: ffffc900113df1e8 RDX: 00000000000000f0 RSI: 0000000000408d40 RDI: ffff888075287d00 RBP: ffff888075287d00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000408d40 R13: 0000000000408d40 R14: 0000000000000400 R15: 00000000000000a8 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: 0033:0x7f4f2b53ae99 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:00007f4f29eb0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f4f2b64df60 RCX: 00007f4f2b53ae99 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 0000000000000005 RBP: 00007f4f2b594ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4187a21f R14: 00007f4f29eb0300 R15: 0000000000022000 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8252 Comm: syz-executor.5 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0xc/0x70 kernel/kcov.c:293 Code: 4c 38 f0 48 c7 44 38 e0 05 00 00 00 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 c3 0f 1f 40 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 <48> 89 f1 65 48 8b 34 25 40 70 02 00 e8 a3 f8 ff ff 84 c0 74 48 48 RSP: 0018:ffffc90000fd8a28 EFLAGS: 00000046 RAX: 0000000080010001 RBX: ffffc90000fd8b20 RCX: 0000000000000000 RDX: ffff888074ee0140 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffffc90000fd8c80 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff819863a2 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88802c274140 R14: 0000000000000000 R15: ffffc90000fd8b20 FS: 00007f8740189700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e538000 CR3: 000000007c7ac000 CR4: 00000000003526e0 Call Trace: <IRQ> perf_prepare_sample+0x1e2/0x1e30 kernel/events/core.c:7314 __perf_event_output kernel/events/core.c:7487 [inline] perf_event_output_forward+0xda/0x280 kernel/events/core.c:7507 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9207 perf_swevent_hrtimer+0x37c/0x3f0 kernel/events/core.c:10600 __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 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_preemption_disabled+0x4/0x170 lib/smp_processor_id.c:13 Code: 00 00 e8 5f d3 56 f8 65 48 8b 3c 25 40 70 02 00 e8 41 09 0e f8 eb 99 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 15 be RSP: 0018:ffffc9001133eff0 EFLAGS: 00000282 RAX: 0000000000000001 RBX: ffffc9001133f0e0 RCX: ffffc900031bb000 RDX: 0000000000000001 RSI: ffffffff8a04a060 RDI: ffffffff8a04a0a0 RBP: 0000000000000015 R08: 0000000000000001 R09: 0000000000000006 R10: ffffffff8401f1e6 R11: 000000000000003f R12: ffff8880376326c0 R13: ffff8880376e6082 R14: 0000000000000000 R15: 0000000000000006 rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1169 [inline] rcu_lockdep_current_cpu_online+0x2d/0x150 kernel/rcu/tree.c:1160 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_held+0x21/0x40 kernel/rcu/update.c:309 xa_entry include/linux/xarray.h:1182 [inline] xas_descend+0x2a5/0x3b0 lib/xarray.c:204 xas_load+0xe5/0x140 lib/xarray.c:240 xa_get_order+0xf7/0x390 lib/xarray.c:1761 __filemap_add_folio+0x364/0xe20 mm/filemap.c:916 filemap_add_folio+0xab/0x1d0 mm/filemap.c:999 __filemap_get_folio+0x3bc/0xe10 mm/filemap.c:1962 pagecache_get_page+0x2c/0x1a0 mm/folio-compat.c:125 ext4_da_write_begin+0x3bc/0xad0 fs/ext4/inode.c:2958 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: 0033:0x7f8741813e99 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:00007f8740189168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f8741926f60 RCX: 00007f8741813e99 RDX: 0000000000000000 RSI: 0000000000000013 RDI: 0000000000000005 RBP: 00007f874186dff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffde473276f R14: 00007f8740189300 R15: 0000000000022000 </TASK> sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 75 0a jne 0xc 2: f6 43 23 04 testb $0x4,0x23(%rbx) 6: 0f 84 97 00 00 00 je 0xa3 c: e8 fe 90 06 00 callq 0x6910f 11: 48 85 c0 test %rax,%rax 14: 48 89 c5 mov %rax,%rbp 17: 0f 84 86 00 00 00 je 0xa3 1d: 8b 53 14 mov 0x14(%rbx),%edx 20: 44 89 e6 mov %r12d,%esi 23: 48 89 c7 mov %rax,%rdi 26: 48 83 c2 08 add $0x8,%rdx * 2a: e8 a0 a5 06 00 callq 0x6a5cf <-- trapping instruction 2f: 85 c0 test %eax,%eax 31: 74 72 je 0xa5 33: e8 a7 7c a5 ff callq 0xffa57cdf 38: 31 d2 xor %edx,%edx 3a: 45 31 c9 xor %r9d,%r9d 3d: 45 31 c0 xor %r8d,%r8d