rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1064/1:b..l P16840/1:b..l rcu: (detected by 1, t=10503 jiffies, g=101821, q=246 ncpus=2) task:syz.4.2720 state:R running task stack:25840 pid:16840 tgid:16838 ppid:15289 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 7a ca 98 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:ffffc9000ba7f388 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200174fe73 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cda40 RDI: ffffffff8bb0f900 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2d244e0 R10: ffffffff96922707 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb9fe0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] get_mem_cgroup_from_mm+0x4b/0x5f0 mm/memcontrol.c:941 __mem_cgroup_charge+0x1a/0x270 mm/memcontrol.c:4453 mem_cgroup_charge include/linux/memcontrol.h:672 [inline] folio_prealloc mm/memory.c:1068 [inline] wp_page_copy mm/memory.c:3335 [inline] do_wp_page+0x1012/0x3430 mm/memory.c:3727 handle_pte_fault mm/memory.c:5537 [inline] __handle_mm_fault+0x2480/0x5660 mm/memory.c:5664 handle_mm_fault+0x498/0xa60 mm/memory.c:5832 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 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: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:ffffc9000ba7f958 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000000000 RSI: ffff888013263180 RDI: 00000000200e5000 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffed100264c7ff R10: ffff888013263fff R11: 0000000000000000 R12: 00000000000e4b80 R13: ffffc9000ba7fd50 R14: ffff888013263000 R15: 00000000200e4e80 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+0x4d2/0x1150 lib/iov_iter.c:185 copy_page_to_iter lib/iov_iter.c:362 [inline] copy_page_to_iter+0xf1/0x180 lib/iov_iter.c:349 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.constprop.0+0x5c9/0x9f0 mm/process_vm_access.c:216 process_vm_rw+0x301/0x360 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+0xe2/0x1c0 mm/process_vm_access.c:292 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: 0033:0x7ff795379eb9 RSP: 002b:00007ff796122038 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007ff795515f80 RCX: 00007ff795379eb9 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 00000000000000c9 RBP: 00007ff7953e793e R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff795515f80 R15: 00007ffe1eb677b8 task:kworker/u8:5 state:R running task stack:22128 pid:1064 tgid:1064 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 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:lockdep_enabled kernel/locking/lockdep.c:121 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5735 [inline] RIP: 0010:lock_acquire+0x138/0x560 kernel/locking/lockdep.c:5724 Code: 0f 85 1d 01 00 00 65 48 8b 15 a4 1a 9a 7e 48 8d ba dc 0a 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 01 <48> 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 b3 03 00 00 8b RSP: 0018:ffffc90004487aa0 EFLAGS: 00000a07 RAX: dffffc0000000000 RBX: 1ffff92000890f56 RCX: 0000000000000000 RDX: ffff888027b83c00 RSI: ffffffff8bb0f880 RDI: ffff888027b846dc RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff202879b R10: ffffffff90143cdf R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb9fe0 R15: 0000000000000000 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+0x16a/0x1060 net/batman-adv/network-coding.c:719 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 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: rcu_preempt kthread starved for 6927 jiffies! g101821 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:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 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:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111