rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=3854/1/0x4000000000000000 softirq=80286/80287 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21996/1:b..l rcu: (detected by 0, t=10505 jiffies, g=125485, q=96 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22062 Comm: syz-executor.5 Not tainted 6.4.0-next-20230706-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5763 [inline] RIP: 0010:lock_acquire+0x1ce/0x520 kernel/locking/lockdep.c:5726 Code: ff 74 24 20 45 0f b6 c9 e8 af 8c ff ff 48 c7 c7 60 73 6c 8a 48 83 c4 28 e8 1f 79 b9 08 b8 ff ff ff ff 65 0f c1 05 42 36 9c 7e <83> f8 01 0f 85 b9 02 00 00 9c 58 f6 c4 02 0f 85 a4 02 00 00 48 83 RSP: 0018:ffffc900001e0c28 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 1ffff9200003c187 RCX: fc76794eeabd53a6 RDX: 1ffff11011c13158 RSI: 0000000000010001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff230dfc0 R10: ffffffff9186fe07 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000001 R14: ffffffff8d35b520 R15: 0000000000000000 FS: 00007f305925e700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00c4d3000 CR3: 00000000629bd000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_objects_fill_pool lib/debugobjects.c:614 [inline] debug_object_activate+0x128/0x4f0 lib/debugobjects.c:713 debug_hrtimer_activate kernel/time/hrtimer.c:422 [inline] debug_activate kernel/time/hrtimer.c:477 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1087 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0xa65/0xc00 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1098 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1115 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1109 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:memory_is_nonzero mm/kasan/generic.c:101 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x64/0x190 mm/kasan/generic.c:187 Code: 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48 89 da 48 29 ea <48> 83 fa 10 0f 8e 8a 00 00 00 41 89 eb 41 83 e3 07 0f 85 97 00 00 RSP: 0018:ffffc9000c56f8d8 EFLAGS: 00000202 RAX: fffff9400028e5a8 RBX: fffff9400028e5a9 RCX: ffffffff81bb58d5 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffea0001472d40 RBP: fffff9400028e5a8 R08: 0000000000000000 R09: fffff9400028e5a8 R10: ffffea0001472d47 R11: 0000000000000001 R12: ffff8880293cb6c0 R13: ffffea0001472d40 R14: dffffc0000000000 R15: 0000000000000cc0 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] folio_test_head include/linux/page-flags.h:769 [inline] folio_test_large include/linux/page-flags.h:790 [inline] folio_order include/linux/mm.h:1061 [inline] shmem_add_to_page_cache+0xa35/0xd50 mm/shmem.c:700 shmem_get_folio_gfp+0x58a/0x1a80 mm/shmem.c:1995 shmem_get_folio mm/shmem.c:2096 [inline] shmem_write_begin+0x14a/0x380 mm/shmem.c:2596 generic_perform_write+0x26b/0x5d0 mm/filemap.c:3925 __generic_file_write_iter+0x1f8/0x240 mm/filemap.c:4020 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4046 call_write_iter include/linux/fs.h:1873 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x981/0xda0 fs/read_write.c:584 ksys_write+0x122/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f305843dfff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007f305925df10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f305843dfff RDX: 0000000001000000 RSI: 00007f304ebff000 RDI: 0000000000000003 RBP: 00007f304ebff000 R08: 0000000000000000 R09: 00000000000097a2 R10: 0000000001000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f305925dfdc R14: 00007f305925dfe0 R15: 00000000200001c2 task:syz-executor.2 state:R running task stack:22496 pid:21996 ppid:19742 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6709 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:7021 irqentry_exit+0x35/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] RIP: 0010:folio_memcg_lock+0x18a/0x6d0 mm/memcontrol.c:2137 Code: 13 df 81 58 e8 b7 35 87 ff 4d 85 ed 0f 85 4b 03 00 00 9c 58 f6 c4 02 0f 85 ee 03 00 00 4d 85 ed 74 01 fb 4c 8d ab 40 09 00 00 04 00 00 00 4c 89 ef e8 49 66 f8 ff 4c 89 e8 48 c1 e8 03 42 0f RSP: 0018:ffffc9000baae880 EFLAGS: 00000206 RAX: 0000000000000002 RBX: ffff88802009e000 RCX: 1ffffffff2316458 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000baae8d0 R08: 0000000000000001 R09: fffffbfff230dfd4 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: ffff88802009e940 R14: ffffea0001472d38 R15: ffffea0001472d08 __folio_start_writeback+0x106/0xa60 mm/page-writeback.c:3016 ext4_bio_write_folio+0x554/0x1ae0 fs/ext4/page-io.c:557 mpage_submit_folio+0x1c9/0x350 fs/ext4/inode.c:1865 mpage_map_and_submit_buffers+0x574/0xaf0 fs/ext4/inode.c:2111 mpage_map_and_submit_extent fs/ext4/inode.c:2251 [inline] ext4_do_writepages+0x196f/0x3290 fs/ext4/inode.c:2677 ext4_writepages+0x304/0x770 fs/ext4/inode.c:2766 do_writepages+0x1a8/0x640 mm/page-writeback.c:2553 filemap_fdatawrite_wbc mm/filemap.c:393 [inline] filemap_fdatawrite_wbc+0x147/0x1b0 mm/filemap.c:383 __filemap_fdatawrite_range+0xb8/0xf0 mm/filemap.c:426 file_write_and_wait_range+0xce/0x140 mm/filemap.c:784 ext4_sync_file+0x254/0xe20 fs/ext4/fsync.c:159 vfs_fsync_range+0x144/0x230 fs/sync.c:188 generic_write_sync include/linux/fs.h:2495 [inline] generic_write_sync include/linux/fs.h:2492 [inline] ext4_buffered_write_iter+0x2fb/0x3d0 fs/ext4/file.c:305 ext4_file_write_iter+0x8f2/0x1880 fs/ext4/file.c:722 __kernel_write_iter+0x262/0x7e0 fs/read_write.c:517 dump_emit_page fs/coredump.c:888 [inline] dump_user_range+0x23c/0x710 fs/coredump.c:915 elf_core_dump+0x27f4/0x3790 fs/binfmt_elf.c:2142 do_coredump+0x2db7/0x3d60 fs/coredump.c:764 get_signal+0x1c16/0x25f0 kernel/signal.c:2863 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:310 exc_page_fault+0xc0/0x170 arch/x86/mm/fault.c:1568 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x9b9beb60 RSP: 002b:00000000200000e8 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fc3127abf80 RCX: 00007fc31268c389 RDX: 0000000020000100 RSI: 00000000200000e0 RDI: 0000000040269000 RBP: 00007fc3126d7493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fffd982919f R14: 00007fc313427300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10505 jiffies! g125485 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:27976 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6709 schedule+0xde/0x1a0 kernel/sched/core.c:6785 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 17068 Comm: kworker/u4:38 Not tainted 6.4.0-next-20230706-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:300 [inline] RIP: 0010:smp_call_function_many_cond+0x694/0x1720 kernel/smp.c:844 Code: 89 ee e8 5f 4f 0b 00 85 ed 74 48 48 8b 44 24 08 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 9e 52 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 d1 0d 00 00 8b 43 08 31 RSP: 0018:ffffc900051ef948 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9943020 RCX: 0000000000000000 RDX: ffff88807dfc8000 RSI: ffffffff817995f2 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffed1017328605 R13: 0000000000000001 R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5c84bfe000 CR3: 000000000c775000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:1012 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1938 [inline] text_poke_bp_batch+0x24f/0x780 arch/x86/kernel/alternative.c:2148 text_poke_flush arch/x86/kernel/alternative.c:2339 [inline] text_poke_flush arch/x86/kernel/alternative.c:2336 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:2346 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:831 [inline] toggle_allocation_gate+0xf8/0x230 mm/kfence/core.c:823 process_one_work+0xa34/0x16f0 kernel/workqueue.c:2597 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2748 kthread+0x344/0x440 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308