rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=01cc/1/0x4000000000000000 softirq=35623/35623 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5835/1:b..l P12/1:b..l P9757/1:b..l P9765/1:b..l rcu: (detected by 1, t=10502 jiffies, g=34525, q=591 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9587 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x80b/0xd80 kernel/locking/lockdep.c:-1 Code: 00 00 00 48 c7 c7 d0 f3 c0 8e 48 89 ee e8 ad d1 a1 03 eb c1 44 89 e0 25 ff 1f 00 00 41 c1 ec 03 41 81 e4 00 60 00 00 41 09 c4 <4c> 89 f8 48 c1 e8 20 89 c1 c1 c1 04 41 29 c4 44 31 e1 44 01 f8 41 RSP: 0018:ffffc90000007b80 EFLAGS: 00000002 RAX: 000000000000006d RBX: 0000000000000000 RCX: 0000000000000008 RDX: 0000000000000008 RSI: ffff88803011e4f0 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000006d R13: ffff88803011da00 R14: ffff88803011e510 R15: ffffffffffffffff FS: 0000555570899500(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3f4b18 CR3: 000000005d9d2000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x67b/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:syscall_enter_from_user_mode_work include/linux/entry-common.h:168 [inline] RIP: 0010:syscall_enter_from_user_mode include/linux/entry-common.h:199 [inline] RIP: 0010:do_syscall_64+0xbc/0x230 arch/x86/entry/syscall_64.c:90 Code: ed 00 00 00 48 8b 7d 08 e8 c1 66 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 c1 2a 9b f5 90 90 e8 6a 2a 9b f5 fb 49 8b 54 24 08 c2 3f 74 0e 4c 89 f7 4c 89 fe e8 f4 c2 7c f5 49 89 c7 90 90 41 RSP: 0018:ffffc9000a81ff10 EFLAGS: 00000286 RAX: 29228bad640d9c00 RBX: ffffc9000a81ff10 RCX: ffffffff81cb469c RDX: 0000000000000000 RSI: ffffffff8e69c6c2 RDI: ffffffff8ca1b6a0 RBP: ffffc9000a81ff48 R08: ffffffff905fe077 R09: 1ffffffff20bfc0e R10: dffffc0000000000 R11: fffffbfff20bfc0f R12: ffff88803011da00 R13: 0000000000000000 R14: ffffc9000a81ff58 R15: 0000000000000003 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f14a4b8c8c7 Code: 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007fff30639ca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f14a4b8c8c7 RDX: 0000000000000000 RSI: 0000000000008933 RDI: 0000000000000005 RBP: 00007fff30639cb0 R08: 0000000000000000 R09: 007664617461625f R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f14a58d4620 R14: 0000000000000006 R15: 0000000000000000 task:syz.6.1304 state:R running task stack:26152 pid:9765 tgid:9764 ppid:7108 task_flags:0x40044c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 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:1761 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x39c5/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd63578d169 RSP: 002b:00007fd6365370e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fd6359a5fa8 RCX: 00007fd63578d169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fd6359a5fac RBP: 00007fd6359a5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 00007fd6359a5fac R13: 0000000000000000 R14: 00007ffc9fc641a0 R15: 00007ffc9fc64288 task:syz.8.1299 state:R running task stack:24936 pid:9757 tgid:9757 ppid:9391 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 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:1761 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x39c5/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5dfe38d169 RSP: 002b:00007fff00a8b828 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5dfe38d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff00a8b88c R08: 0000000400a8b91f R09: 00000000000927c0 R10: 000000000000a08c R11: 0000000000000246 R12: 000000000000000a R13: 00000000000927c0 R14: 0000000000042186 R15: 00007fff00a8b8e0 task:kworker/u8:0 state:R running task stack:21128 pid:12 tgid:12 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 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+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90000117a38 EFLAGS: 00000206 RAX: 2710b0e7d1fc1d00 RBX: ffffffff8ed3dfe0 RCX: 2710b0e7d1fc1d00 RDX: 0000000000000000 RSI: ffffffff8e4fd53d RDI: ffffffff8ca1b6a0 RBP: ffffffff9368a020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [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:3238 [inline] process_scheduled_works+0xac5/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:20552 pid:5835 tgid:5835 ppid:5834 task_flags:0x400140 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 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] copy_pte_range+0x5e5f/0x6680 mm/memory.c:1194 copy_pmd_range mm/memory.c:1255 [inline] copy_pud_range mm/memory.c:1292 [inline] copy_p4d_range mm/memory.c:1316 [inline] copy_page_range+0xe57/0x13a0 mm/memory.c:1410 dup_mmap kernel/fork.c:726 [inline] dup_mm kernel/fork.c:1734 [inline] copy_mm+0x130d/0x22c0 kernel/fork.c:1786 copy_process+0x17de/0x3d10 kernel/fork.c:2429 kernel_clone+0x242/0x930 kernel/fork.c:2844 __do_sys_clone kernel/fork.c:2987 [inline] __se_sys_clone kernel/fork.c:2971 [inline] __x64_sys_clone+0x268/0x2e0 kernel/fork.c:2971 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f23899839d3 RSP: 002b:00007ffc309d53a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f23899839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556c5f97d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000004234b R15: 00007ffc309d5540 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g34525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=19049 rcu: rcu_preempt kthread starved for 10502 jiffies! g34525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245