rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ac24/1/0x4000000000000000 softirq=41237/41238 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2997/1:b..l rcu: (detected by 0, t=10505 jiffies, g=35997, q=1656 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9855 Comm: syz.0.1168 Not tainted 6.15.0-syzkaller-13526-g7a912d04415b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_release+0xaf/0x3e0 kernel/locking/lockdep.c:5888 Code: 0a 00 00 00 0f 85 1e 02 00 00 49 81 3e 40 63 5d 93 0f 84 11 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 48 c7 c7 52 15 98 8d e8 d4 ad c0 09 65 ff 05 cd aa fb 10 c7 44 RSP: 0018:ffffc90000a08c08 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 82480a3499935700 RDX: 0000000000010000 RSI: ffffffff8be1afa0 RDI: ffffffff8be1af60 RBP: 0000000000000001 R08: ffff888028bb815f R09: 1ffff1100517702b R10: dffffc0000000000 R11: ffffed100517702c R12: ffff888028bb8360 R13: ffffffff897e8248 R14: ffffffff8e13f060 R15: ffff888055641e00 FS: 0000000000000000(0000) GS:ffff888125d86000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b305129c0 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:987 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:folio_test_slab include/linux/page-flags.h:1074 [inline] RIP: 0010:PageSlab include/linux/page-flags.h:1085 [inline] RIP: 0010:page_table_check_clear+0xf8/0x700 mm/page_table_check.c:74 Code: b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 3d 04 00 00 41 0f b6 6c 24 03 c1 e5 18 bf 00 00 00 f5 89 ee e8 78 a3 93 ff <81> fd 00 00 00 f5 0f 84 5a 04 00 00 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000cbb7590 EFLAGS: 00000293 RAX: ffffffff822cab98 RBX: 1ffffd40002fd1d1 RCX: 0000000000000000 RDX: ffff888055641e00 RSI: 0000000000000000 RDI: 00000000f5000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff822cc52a R10: dffffc0000000000 R11: fffff940002fd1d1 R12: ffffea00017e8eb0 R13: ffffea00017e8e80 R14: 0000000000000001 R15: ffffea00017e8e88 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1505 [inline] zap_present_ptes mm/memory.c:1590 [inline] do_zap_pte_range mm/memory.c:1691 [inline] zap_pte_range mm/memory.c:1735 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x3249/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ddc78e929 Code: Unable to access opcode bytes at 0x7f6ddc78e8ff. RSP: 002b:00007ffd9ee401c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6ddc78e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd9ee4022c R08: 000000039ee402bf R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000011f R13: 00000000000927c0 R14: 00000000000685bf R15: 00007ffd9ee40280 task:kworker/u8:9 state:R running task stack:20168 pid:2997 tgid:2997 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_is_watching+0x9/0xb0 kernel/rcu/tree.c:744 Code: 48 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 <65> ff 05 d0 8a f2 10 e8 7b cc b7 09 89 c3 83 f8 08 73 65 49 bf 00 RSP: 0018:ffffc9000b227a00 EFLAGS: 00000202 RAX: ffffffff8b2c9223 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88802fa73c00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88807b851898 R08: 0000000000000000 R09: ffffffff8b2c91f2 R10: dffffc0000000000 R11: ffffffff8b2c9120 R12: dffffc0000000000 R13: ffffffff8b2c91f2 R14: ffff888057ad8d80 R15: 0000000000000313 rcu_read_lock include/linux/rcupdate.h:842 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x10c/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10495 jiffies! g35997 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:26824 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 5840 Comm: syz-executor Not tainted 6.15.0-syzkaller-13526-g7a912d04415b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 50 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 fb 73 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 e0 73 0b RSP: 0018:ffffc900045cf580 EFLAGS: 00000293 RAX: ffffffff81b4d6f0 RBX: ffff8880b863c9c0 RCX: ffff8880350b9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900045cf6e0 R08: ffffffff8f9fe8f7 R09: 1ffffffff1f3fd1e R10: dffffc0000000000 R11: fffffbfff1f3fd1f R12: 1ffff110170e825d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b87412e8 FS: 0000555572ba0500(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb6ba5cd58 CR3: 0000000075d20000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 dup_mmap+0x15a0/0x1ac0 mm/mmap.c:1877 dup_mm kernel/fork.c:1477 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1529 copy_process+0x1706/0x3c00 kernel/fork.c:2169 kernel_clone+0x224/0x7f0 kernel/fork.c:2599 __do_sys_clone kernel/fork.c:2742 [inline] __se_sys_clone kernel/fork.c:2726 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f015df85193 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffec7147ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f015df85193 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555572ba07d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000067fe3 R15: 00007ffec7148090