rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3674/1:b..l (detected by 1, t=10503 jiffies, g=6033, q=39 ncpus=2) task:syz-executor.4 state:R running task stack:24728 pid:3674 ppid:3567 flags:0x0000400e Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:658 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 cf aa 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0000:ffffc90004716f60 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008e2df8 RCX: 1ffff920008e2d98 RDX: dffffc0000000000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d4520 RBP: ffffc900047170b8 R08: dffffc0000000000 R09: fffffbfff2093a45 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920008e2df4 R13: dffffc0000000000 R14: ffffc90004716fc0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] page_ext_get+0x39/0x2a0 mm/page_ext.c:157 __page_table_check_zero+0x139/0x4a0 mm/page_table_check.c:140 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547 __folio_alloc+0xf/0x30 mm/page_alloc.c:5579 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243 shmem_alloc_folio mm/shmem.c:1589 [inline] shmem_alloc_and_acct_folio+0x5a8/0xd50 mm/shmem.c:1613 shmem_get_folio_gfp+0x13f0/0x3470 mm/shmem.c:1941 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0x16e/0x4e0 mm/shmem.c:2559 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3817 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3945 generic_file_write_iter+0xab/0x310 mm/filemap.c:3977 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ae/0xba0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f142fa7bbef RSP: 002b:00007f1430757e80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f142fa7bbef RDX: 0000000001000000 RSI: 00007f14261f7000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050e1 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f1430757f80 R14: 00007f1430757f40 R15: 00007f14261f7000 rcu: rcu_preempt kthread starved for 10550 jiffies! g6033 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:26712 pid:16 ppid:2 flags:0x00004008 Call Trace: sched_show_task+0x4d5/0x670 kernel/sched/core.c:8942 rcu_check_gp_kthread_starvation+0x180/0x220 kernel/rcu/tree_stall.h:515 print_other_cpu_stall+0x150c/0x1640 kernel/rcu/tree_stall.h:625 check_cpu_stall kernel/rcu/tree_stall.h:778 [inline] rcu_pending kernel/rcu/tree.c:3890 [inline] rcu_sched_clock_irq+0xaf6/0x1200 kernel/rcu/tree.c:2393 update_process_times+0x147/0x1b0 kernel/time/timer.c:1869 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1501 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5a7/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 0b 32 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc90000157808 EFLAGS: 00000286 RAX: 30dd4648096bb300 RBX: ffff888024d99df4 RCX: ffffffff91c95103 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed6f38 RBP: ffffc90000157850 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:661 RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31 Code: 41 5e 41 5f 5d c3 48 c7 c7 75 e4 90 8c eb 0a 48 c7 c7 ad e4 90 8c 4c 89 fe e8 46 10 a7 08 31 db eb d7 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 d3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 RSP: 0018:ffffc90000157b90 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 1ffff11027fdab28 RCX: ffffffff8a93a8f6 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88813fed5940 RBP: ffffc90000157cb0 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff9200002af78 R14: ffff88813fed6bb8 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] test_ti_thread_flag include/linux/thread_info.h:118 [inline] need_resched include/linux/sched.h:2231 [inline] schedule+0xd6/0x180 kernel/sched/core.c:6636 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 16 Comm: rcu_preempt Not tainted 6.1.93-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 0b 32 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc90000157808 EFLAGS: 00000286 RAX: 30dd4648096bb300 RBX: ffff888024d99df4 RCX: ffffffff91c95103 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed6f38 RBP: ffffc90000157850 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32835000 CR3: 00000000228d7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:661 RIP: 0010:__kasan_check_read+0x6/0x10 mm/kasan/shadow.c:31 Code: 41 5e 41 5f 5d c3 48 c7 c7 75 e4 90 8c eb 0a 48 c7 c7 ad e4 90 8c 4c 89 fe e8 46 10 a7 08 31 db eb d7 cc cc 89 f6 48 8b 0c 24 <31> d2 e9 d3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24 ba 01 00 00 00 e9 RSP: 0018:ffffc90000157b90 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 1ffff11027fdab28 RCX: ffffffff8a93a8f6 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff88813fed5940 RBP: ffffc90000157cb0 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff9200002af78 R14: ffff88813fed6bb8 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] test_ti_thread_flag include/linux/thread_info.h:118 [inline] need_resched include/linux/sched.h:2231 [inline] schedule+0xd6/0x180 kernel/sched/core.c:6636 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308