rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18658/1:b..l P28671/1:b..l rcu: (detected by 0, t=10502 jiffies, g=213821, q=163 ncpus=2) task:syz-executor.5 state:R running task stack:25456 pid:28671 tgid:28671 ppid:26075 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 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 5a 2e 88 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:ffffc90004eeee20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920009dddd0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca20 RDI: ffffffff8c1f8260 RBP: ffffc90004eeef68 R08: ffffffff92f35507 R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: 1ffff920009dddcc R13: dffffc0000000000 R14: ffffc90004eeee80 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] is_bpf_text_address+0x42/0x2b0 kernel/bpf/core.c:767 kernel_text_address+0xa7/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3851 [inline] kmem_cache_alloc_lru+0x178/0x360 mm/slub.c:3870 __d_alloc+0x31/0x700 fs/dcache.c:1624 d_alloc fs/dcache.c:1704 [inline] d_alloc_parallel+0xdf/0x1600 fs/dcache.c:2462 __lookup_slow+0x117/0x3f0 fs/namei.c:1677 lookup_slow+0x53/0x70 fs/namei.c:1709 walk_component+0x2e1/0x410 fs/namei.c:2004 link_path_walk+0x728/0xea0 fs/namei.c:2328 path_openat+0x24a/0x3240 fs/namei.c:3795 do_filp_open+0x235/0x490 fs/namei.c:3826 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 do_sys_open fs/open.c:1421 [inline] __do_sys_openat fs/open.c:1437 [inline] __se_sys_openat fs/open.c:1432 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1432 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7facc467c960 RSP: 002b:00007ffeec373d80 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000080001 RCX: 00007facc467c960 RDX: 0000000000080001 RSI: 00007facc46ca526 RDI: 00000000ffffff9c RBP: 00007facc46ca526 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004 R13: 00007ffeec373e20 R14: 0000000000000001 R15: 0000000000000001 task:kworker/u8:6 state:R running task stack:20400 pid:18658 tgid:18658 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 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:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:696 Code: 4c 89 f6 e8 82 ef 6c 03 e9 2b ff ff ff e8 18 f4 03 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 65 ff 05 68 78 87 7e e8 4b 12 04 0a 89 RSP: 0018:ffffc900049dfb50 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88801c3b1e00 RDX: ffff88801c3b1e00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8b4b0dbe R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: ffff88805f26cca0 R13: 000000000000007c R14: ffff88801f560700 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:810 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x207/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f2/0x390 kernel/kthread.c:388 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 10007 jiffies! g213821 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:26256 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112