rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5825/1:b..l (detected by 0, t=10502 jiffies, g=16665, q=425) task:syz-executor.5 state:R running task stack:27912 pid: 5825 ppid: 3646 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6711 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5607 Code: 8f a5 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:ffffc90006f37420 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000de6e86 RCX: bf45aa0a9b02e1ff RDX: 1ffff110038c2c44 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ffbb947 R10: fffffbfff1ff7728 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bb82920 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:694 [inline] is_bpf_text_address+0x36/0x170 kernel/bpf/core.c:715 kernel_text_address kernel/extable.c:124 [inline] kernel_text_address+0x39/0x80 kernel/extable.c:93 __kernel_text_address+0x9/0x30 kernel/extable.c:78 unwind_get_return_address arch/x86/kernel/unwind_orc.c:318 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:313 arch_stack_walk+0x93/0xe0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 save_stack+0x151/0x1e0 mm/page_owner.c:121 __reset_page_owner+0x5d/0x180 mm/page_owner.c:142 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x414/0xb60 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3441 release_pages+0x818/0x18e0 mm/swap.c:980 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline] tlb_flush_mmu_free mm/mmu_gather.c:243 [inline] tlb_flush_mmu mm/mmu_gather.c:250 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:341 exit_mmap+0x21b/0x670 mm/mmap.c:3181 __mmput+0x122/0x4b0 kernel/fork.c:1116 mmput+0x56/0x60 kernel/fork.c:1137 exit_mm kernel/exit.c:507 [inline] do_exit+0xa44/0x2b10 kernel/exit.c:780 do_group_exit+0x128/0x330 kernel/exit.c:932 get_signal+0x4b0/0x28c0 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f947771ee99 RSP: 002b:00007f9476094218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f9477831f68 RCX: 00007f947771ee99 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9477831f68 RBP: 00007f9477831f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9477831f6c R13: 00007ffde19d766f R14: 00007f9476094300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10500 jiffies! g16665 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28720 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:1972 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2145 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5828 Comm: syz-executor.3 Not tainted 5.16.0-rc8-next-20220105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x8/0x70 kernel/kcov.c:295 Code: c2 01 48 89 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 00 70 02 00 e8 a3 f8 ff ff 84 RSP: 0018:ffffc90000dc09e8 EFLAGS: 00000046 RAX: 0000000080010001 RBX: ffff888078f65e00 RCX: 0000000000000000 RDX: ffff888022900000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffffc90000dc0c80 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff819787c9 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000008 R15: ffffc90000dc0b20 FS: 00007f9ec9bcb700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f329000 CR3: 000000006c3f3000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __perf_event_header__init_id+0x177/0x600 kernel/events/core.c:6836 perf_prepare_sample+0x1b9/0x1f20 kernel/events/core.c:7330 __perf_event_output kernel/events/core.c:7508 [inline] perf_event_output_forward+0xda/0x280 kernel/events/core.c:7528 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9228 perf_swevent_hrtimer+0x37c/0x3f0 kernel/events/core.c:10621 __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:unwind_next_frame+0x830/0x1ce0 arch/x86/kernel/unwind_orc.c:466 Code: 07 38 d0 7f 08 84 c0 0f 85 12 12 00 00 41 80 7e 34 00 0f 85 00 fc ff ff 80 3d f4 df 4a 0c 00 0f 85 f3 fb ff ff e9 25 10 de 07 <48> b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90006f46cb8 EFLAGS: 00000297 RAX: 0000000000000005 RBX: 1ffff92000de8d9f RCX: ffffffff8e1be005 RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8e1be000 R09: 0000000000000001 R10: fffff52000de8dbd R11: 0000000000088077 R12: ffffc90006f46dd8 R13: ffffc90006f46dc5 R14: ffffc90006f46d90 R15: ffffffff8e1be004 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 save_stack+0x151/0x1e0 mm/page_owner.c:121 __set_page_owner+0x45/0x2d0 mm/page_owner.c:183 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f40 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5381 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 folio_alloc+0x1c/0x70 mm/mempolicy.c:2281 filemap_alloc_folio mm/filemap.c:989 [inline] __filemap_get_folio+0x60e/0xef0 mm/filemap.c:1992 pagecache_get_page+0x2e/0x280 mm/folio-compat.c:125 ext4_da_write_begin+0x3bb/0xba0 fs/ext4/inode.c:2943 generic_perform_write+0x205/0x510 mm/filemap.c:3767 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:2074 [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+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: 0033:0x7f9ecb255e99 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:00007f9ec9bcb168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f9ecb368f60 RCX: 00007f9ecb255e99 RDX: 0000000000000000 RSI: 000000000000000d RDI: 0000000000000006 RBP: 00007f9ecb2afff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd86c40e6f R14: 00007f9ec9bcb300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess), 1 bytes skipped: 0: a5 movsl %ds:(%rsi),%es:(%rdi) 1: 7e 83 jle 0xffffff86 3: f8 clc 4: 01 0f add %ecx,(%rdi) 6: 85 b4 02 00 00 9c 58 test %esi,0x589c0000(%rdx,%rax,1) d: f6 c4 02 test $0x2,%ah 10: 0f 85 9f 02 00 00 jne 0x2b5 16: 48 83 7c 24 08 00 cmpq $0x0,0x8(%rsp) 1c: 74 01 je 0x1f 1e: fb sti 1f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 26: fc ff df * 29: 48 01 c3 add %rax,%rbx <-- trapping instruction 2c: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 33: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 3a: 00 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 84 .byte 0x84 3e: 24 .byte 0x24