rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12096/1:b..l P12093/1:b..l rcu: (detected by 0, t=10502 jiffies, g=58933, q=527 ncpus=2) task:syz-executor.0 state:R running task stack:26224 pid:12093 tgid:12092 ppid:11597 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 ba 3a 86 00 f6 44 24 61 02 0f 85 85 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: 0018:ffffc90004367100 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200086ce2c RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcacd00 RDI: ffffffff8c1f2480 RBP: ffffc90004367258 R08: ffffffff92f74587 R09: 1ffffffff25ee8b0 R10: dffffc0000000000 R11: fffffbfff25ee8b1 R12: 1ffff9200086ce28 R13: dffffc0000000000 R14: ffffc90004367160 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:521 __set_page_owner+0x9e/0x800 mm/page_owner.c:322 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468 prep_new_page mm/page_alloc.c:1476 [inline] get_page_from_freelist+0x2e43/0x2f00 mm/page_alloc.c:3420 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4678 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 shmem_alloc_folio mm/shmem.c:1628 [inline] shmem_alloc_and_add_folio+0x24d/0xdb0 mm/shmem.c:1668 shmem_get_folio_gfp+0x82d/0x1f50 mm/shmem.c:2055 shmem_get_folio mm/shmem.c:2160 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2743 generic_perform_write+0x322/0x640 mm/filemap.c:4015 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2919 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f5ea7bbef RSP: 002b:00007f8f5e5fee80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f8f5ea7bbef RDX: 0000000000100000 RSI: 00007f8f54800000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000c37 R10: 00000000000007c8 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f8f5e5fef80 R14: 00007f8f5e5fef40 R15: 00007f8f54800000 task:syz-executor.1 state:R running task stack:26816 pid:12096 tgid:12088 ppid:11388 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:212 Code: ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc90004247758 EFLAGS: 00000246 RAX: ffffffff8b78f694 RBX: ffffc90004247838 RCX: ffff888051930000 RDX: ffffc9000ed89000 RSI: 00000000000093c5 RDI: ffffc90004247820 RBP: dffffc0000000000 R08: ffffffff81cc7d38 R09: 1ffffffff25ee8b0 R10: dffffc0000000000 R11: fffffbfff25ee8b1 R12: ffffc90004247820 R13: 1ffff92000848f00 R14: ffffffff81cc7d07 R15: dffffc0000000000 xas_load+0x24/0x5c0 lib/xarray.c:237 filemap_get_entry+0x1fe/0x4e0 mm/filemap.c:1840 shmem_get_folio_gfp+0x2a8/0x1f50 mm/shmem.c:1982 shmem_get_folio mm/shmem.c:2160 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2743 generic_perform_write+0x322/0x640 mm/filemap.c:4015 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2919 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f953787bbef RSP: 002b:00007f953853ae80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f953787bbef RDX: 0000000000040000 RSI: 00007f952d600000 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000044c R10: 00000000000003ba R11: 0000000000000293 R12: 000000000000000b R13: 00007f953853af80 R14: 00007f953853af40 R15: 00007f952d600000 rcu: rcu_preempt kthread starved for 10587 jiffies! g58933 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:26008 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x1796/0x49d0 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 35 Comm: kworker/u8:2 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1860/0x29d0 kernel/smp.c:855 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 99 09 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 44 05 0c 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 28 05 RSP: 0018:ffffc90000ab7700 EFLAGS: 00000293 RAX: ffffffff818a20e8 RBX: 1ffff11017288c11 RCX: ffff88801b2d3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000ab78e0 R08: ffffffff818a20b7 R09: 1ffffffff25ee8b0 R10: dffffc0000000000 R11: fffffbfff25ee8b1 R12: dffffc0000000000 R13: ffff8880b9446088 R14: ffff8880b953f8c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000147a3f8 CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2069 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2279 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2477 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244