rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13847/1:b..l P9028/1:b..l P13896/1:b..l rcu: (detected by 1, t=10502 jiffies, g=94865, q=404 ncpus=2) task:syz-executor.3 state:R running task stack:26656 pid:13896 tgid:13895 ppid:9791 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:303 Code: 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 58 fe ff ff 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 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff RSP: 0018:ffffc90003717708 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff888065c13c98 RCX: ffffc900120f5000 RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000004 R12: 0000000000000001 R13: ffffc90003717830 R14: 0000000000000002 R15: 0000000000000300 mt_find+0x5ca/0xa20 lib/maple_tree.c:6936 find_vma+0xc0/0x140 mm/mmap.c:1948 lock_mm_and_find_vma+0x62/0x6a0 mm/memory.c:5778 do_user_addr_fault+0x29c/0xe50 arch/x86/mm/fault.c:1361 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:fault_in_readable+0x106/0x200 mm/gup.c:2341 Code: ff 0f 00 00 31 c0 4c 89 eb 48 81 e5 00 f0 ff ff 4c 39 ed 48 0f 42 e8 e8 08 98 bd ff 48 39 dd 0f 84 e4 00 00 00 e8 fa 97 bd ff <44> 8a 3b e8 f2 97 bd ff 48 81 c3 00 10 00 00 44 88 7c 24 20 48 39 RSP: 0018:ffffc900037179f0 EFLAGS: 00050246 RAX: 0000000000040000 RBX: 0000000020242000 RCX: ffffc900120f5000 RDX: 0000000000040000 RSI: ffffffff81d04d56 RDI: 0000000000000007 RBP: 0000000020243000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000001000 R13: 0000000020242000 R14: 1ffff920006e2f3e R15: 0000000000000000 fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94 generic_perform_write+0x1cc/0x620 mm/filemap.c:4005 ext4_buffered_write_iter+0x11f/0x3d0 fs/ext4/file.c:299 ext4_file_write_iter+0x874/0x1a40 fs/ext4/file.c:698 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f733047cf69 RSP: 002b:00007f733124d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f73305b3f80 RCX: 00007f733047cf69 RDX: 00000000ffffff6a RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007f73304da6fe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f73305b3f80 R15: 00007ffc82af2af8 task:kworker/u8:0 state:R running task stack:24424 pid:9028 tgid:9028 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5722 Code: c1 05 3a af 96 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90003787aa0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920006f0f56 RCX: 0000000061129074 RDX: 0000000000000001 RSI: ffffffff8b2cb240 RDI: ffffffff8b900080 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff284dc58 R10: ffffffff9426e2c7 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8dbb1920 R15: 0000000000000000 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+0x16e/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 task:syz-executor.0 state:R running task stack:25536 pid:13847 tgid:13845 ppid:12336 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6924 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1682 [inline] zap_pmd_range mm/memory.c:1730 [inline] zap_pud_range mm/memory.c:1759 [inline] zap_p4d_range mm/memory.c:1780 [inline] unmap_page_range+0xbc7/0x41e0 mm/memory.c:1801 unmap_single_vma+0x194/0x2b0 mm/memory.c:1847 unmap_vmas+0x22f/0x490 mm/memory.c:1891 exit_mmap+0x1b8/0xb20 mm/mmap.c:3341 __mmput+0x12a/0x4d0 kernel/fork.c:1346 mmput+0x62/0x70 kernel/fork.c:1368 exit_mm kernel/exit.c:565 [inline] do_exit+0x9b7/0x2ba0 kernel/exit.c:861 do_group_exit+0xd3/0x2a0 kernel/exit.c:1023 get_signal+0x2616/0x2710 kernel/signal.c:2909 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f36d827cf69 RSP: 002b:00007f36d8f270c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: 00000000007ffb80 RBX: 00007f36d83b3f80 RCX: 00007f36d827cf69 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 00000000000000b7 RBP: 00007f36d82da6fe R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f36d83b3f80 R15: 00007ffda7aeec48 rcu: rcu_preempt kthread starved for 10227 jiffies! g94865 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:27200 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112