rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P35/1:b..l P9925/1:b..l P9935/1:b..l rcu: (detected by 1, t=10502 jiffies, g=42993, q=162 ncpus=2) task:syz.1.1141 state:R running task stack:21632 pid:9935 tgid:9933 ppid:5223 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6925 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:5826 Code: 2b 00 74 08 4c 89 f7 e8 aa 9e 8b 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:ffffc9000b82f4a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92001705ea0 RCX: 95d9a74a10b1ac00 RDX: dffffc0000000000 RSI: ffffffff8c0ae6c0 RDI: ffffffff8c607c40 RBP: ffffc9000b82f5e8 R08: ffffffff93737807 R09: 1ffffffff26e6f00 R10: dffffc0000000000 R11: fffffbfff26e6f01 R12: 1ffff92001705e9c R13: dffffc0000000000 R14: ffffc9000b82f500 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] blk_cgroup_congested+0x38/0x200 block/blk-cgroup.c:2191 __folio_throttle_swaprate+0x84/0x1d0 mm/swapfile.c:3742 folio_throttle_swaprate include/linux/swap.h:641 [inline] shmem_add_to_page_cache+0x89c/0x1830 mm/shmem.c:796 shmem_alloc_and_add_folio+0x90b/0x14e0 mm/shmem.c:1814 shmem_get_folio_gfp+0x8dc/0x2370 mm/shmem.c:2192 shmem_get_folio mm/shmem.c:2297 [inline] shmem_write_begin+0x170/0x4d0 mm/shmem.c:2902 generic_perform_write+0x399/0x840 mm/filemap.c:4019 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:3078 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: 0033:0x7f5f2f375e1f RSP: 002b:00007f5f301b1e00 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f5f2f375e1f RDX: 0000000001000000 RSI: 00007f5f24a00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000050f0 R10: 0000000020000342 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f5f301b1f00 R14: 00007f5f301b1ec0 R15: 00007f5f24a00000 task:syz.4.1138 state:R running task stack:23664 pid:9925 tgid:9919 ppid:6289 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6782 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6806 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] wp_page_copy mm/memory.c:3436 [inline] do_wp_page+0x1da4/0x52f0 mm/memory.c:3727 handle_pte_fault+0x1138/0x6eb0 mm/memory.c:5538 __handle_mm_fault mm/memory.c:5665 [inline] handle_mm_fault+0x1029/0x1980 mm/memory.c:5833 do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc900184bf958 EFLAGS: 00050206 RAX: ffff888013107001 RBX: 00000000203c7e80 RCX: 0000000000000e80 RDX: 0000000000000000 RSI: ffff888013107180 RDI: 00000000203c7000 RBP: ffffc900184bfad8 R08: ffff888013107fff R09: 1ffff11002620fff R10: dffffc0000000000 R11: ffffed1002621000 R12: dffffc0000000000 R13: 1ffff92003097f40 R14: 0000000000001000 R15: ffff888013107000 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:51 [inline] iterate_and_advance2 include/linux/iov_iter.h:247 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x4c0/0x1960 lib/iov_iter.c:185 copy_page_to_iter+0xb1/0x160 lib/iov_iter.c:362 process_vm_rw_pages mm/process_vm_access.c:45 [inline] process_vm_rw_single_vec mm/process_vm_access.c:118 [inline] process_vm_rw_core mm/process_vm_access.c:216 [inline] process_vm_rw+0x871/0xcf0 mm/process_vm_access.c:284 __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline] __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline] __x64_sys_process_vm_readv+0xe0/0x100 mm/process_vm_access.c:292 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: 0033:0x7faf09177299 RSP: 002b:00007faf09f17048 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007faf09306058 RCX: 00007faf09177299 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 00000000000001f4 RBP: 00007faf091e48e6 R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007faf09306058 R15: 00007ffde66c93a8 task:kworker/u8:2 state:R running task stack:22624 pid:35 tgid:35 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6925 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5826 Code: 2b 00 74 08 4c 89 f7 e8 aa 9e 8b 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:ffffc90000ab79e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000156f48 RCX: e9ff4bd1a59af900 RDX: dffffc0000000000 RSI: ffffffff8c0ae6c0 RDI: ffffffff8c607c40 RBP: ffffc90000ab7b40 R08: ffffffff93737807 R09: 1ffffffff26e6f00 R10: dffffc0000000000 R11: fffffbfff26e6f01 R12: 1ffff92000156f44 R13: dffffc0000000000 R14: ffffc90000ab7a40 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [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+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10092 jiffies! g42993 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:26576 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 __schedule_loop kernel/sched/core.c:6680 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6695 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 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:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111