rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17514/1:b..l P28113/1:b..l rcu: (detected by 0, t=10502 jiffies, g=211765, q=640 ncpus=2) task:syz-executor.4 state:R running task stack:23024 pid:28113 tgid:28111 ppid:24409 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 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:get_stack_info+0x10f/0x180 arch/x86/kernel/dumpstack_64.c:213 Code: c0 eb e8 41 8b 1f bf 40 00 00 00 89 de e8 99 c9 62 00 48 83 fb 3f 77 61 e8 4e c5 62 00 b8 01 00 00 00 89 d9 48 d3 e0 49 09 06 <31> c0 eb bd 80 3d 12 63 64 0e 01 75 07 e8 2f c5 62 00 eb a1 e8 28 RSP: 0018:ffffc9000459f0c0 EFLAGS: 00000202 RAX: 0000000000000002 RBX: 0000000000000001 RCX: 0000000000000001 RDX: ffffc90020a1d000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000000 R08: ffffffff81335127 R09: ffffc9000459f160 R10: dffffc0000000000 R11: fffff520008b3e38 R12: 0000000000000001 R13: ffff8880228a5a00 R14: ffffc9000459f180 R15: ffffc9000459f160 __unwind_start+0x481/0x7c0 arch/x86/kernel/unwind_orc.c:729 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1088 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2565 vfree+0x186/0x2e0 mm/vmalloc.c:3346 bch2_fs_btree_write_buffer_exit+0x174/0x1b0 fs/bcachefs/btree_write_buffer.c:653 __bch2_fs_free fs/bcachefs/super.c:565 [inline] bch2_fs_release+0x2ca/0x6d0 fs/bcachefs/super.c:603 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x231/0x480 lib/kobject.c:737 bch2_fs_stop fs/bcachefs/super.c:673 [inline] bch2_fs_open+0xb57/0xdf0 fs/bcachefs/super.c:2139 bch2_mount+0x71d/0x1310 fs/bcachefs/fs.c:1917 legacy_get_tree+0xf0/0x190 fs/fs_context.c:662 vfs_get_tree+0x92/0x2a0 fs/super.c:1780 do_new_mount+0x2be/0xb40 fs/namespace.c:3352 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 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: 0033:0x7fe60007e5ea RSP: 002b:00007fe600d83ef8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe600d83f80 RCX: 00007fe60007e5ea RDX: 0000000020005d80 RSI: 0000000020005dc0 RDI: 00007fe600d83f40 RBP: 0000000020005d80 R08: 00007fe600d83f80 R09: 0000000000000018 R10: 0000000000000018 R11: 0000000000000206 R12: 0000000020005dc0 R13: 00007fe600d83f40 R14: 0000000000005d7e R15: 00000000200005c0 task:kworker/u8:20 state:R running task stack:18360 pid:17514 tgid:17514 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 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+0x21/0x550 kernel/locking/lockdep.c:5722 Code: 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 01 00 00 4c 89 4c 24 28 <4c> 89 44 24 38 48 89 4c 24 30 89 54 24 1c 41 89 f6 48 89 7c 24 20 RSP: 0018:ffffc9000c93f9e0 EFLAGS: 00000282 RAX: ffffffff8b50c61b RBX: ffff88801ef8e740 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e333f60 RBP: ffffc9000c93fb40 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f5a88e R12: ffff88804f1f8ca0 R13: 00000000000001e0 R14: ffff88801ef8e740 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10064 jiffies! g211765 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-rc1-syzkaller-00021-ge0cce98fe279 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 00 d5 03 00 48 f7 00 08 00 00 00 75 10 eb 07 0f 00 2d b5 14 a3 00 f3 0f 1e fa fb f4 e9 54 d3 29 00 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007ca8 EFLAGS: 00000246 RAX: ffffffff8e094680 RBX: ffff8880182ee064 RCX: 00000000001d3809 RDX: 0000000000000001 RSI: ffff8880182ee000 RDI: ffff8880182ee064 RBP: 000000000003a5b8 R08: ffff8880b9437d0b R09: 1ffff11017286fa1 R10: dffffc0000000000 R11: ffffffff8b866960 R12: ffff88801ab84000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8eace2c0 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe6c2facf00 CR3: 0000000078b28000 CR4: 0000000000350ef0 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x114/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:332 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430 rest_init+0x2dc/0x300 init/main.c:747 start_kernel+0x47a/0x500 init/main.c:1103 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147