rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22591/1:b..l rcu: (detected by 0, t=10503 jiffies, g=168597, q=868 ncpus=2) task:syz.8.4018 state:R running task stack:21512 pid:22591 tgid:22591 ppid:20326 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x1174/0x2390 arch/x86/kernel/unwind_orc.c:641 Code: 8b 14 24 4d 89 65 00 41 0f b6 04 2f 84 c0 0f 85 f9 0f 00 00 c6 03 00 4c 8b 64 24 10 4c 8b 7c 24 28 48 8b 44 24 40 0f b6 04 28 <84> c0 0f 85 8a 0d 00 00 41 0f b6 04 2f 84 c0 0f 85 a1 0d 00 00 0f RSP: 0018:ffffc9000d6decb8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000d6dee20 RCX: 0000000000000000 RDX: ffffffff900aaf84 RSI: 0000000000000000 RDI: ffffc9000d6dee48 RBP: dffffc0000000000 R08: ffffc9000d6dee47 R09: 0000000000000000 R10: ffffc9000d6dee38 R11: fffff52001adbdc9 R12: ffffc9000d6dede8 R13: ffffc9000d6dee38 R14: ffffc9000d6dede8 R15: 1ffffffff20155f0 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73 exc_general_protection+0x171/0x200 arch/x86/kernel/traps.c:792 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:612 RIP: 0033:0x7fd7cc78f6d1 RSP: 002b:00002000000003b0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fd7cc9e6180 RCX: 00007fd7cc78f6c9 RDX: 00002000000001c0 RSI: 00002000000003b0 RDI: 0000000000000080 RBP: 00007fd7cc811f91 R08: 00002000000003c0 R09: 00002000000003c0 R10: 0000200000000200 R11: 0000000000000202 R12: 0000000000000000 R13: 00007fd7cc9e6218 R14: 00007fd7cc9e6180 R15: 00007fd7ccb0fa28 rcu: rcu_preempt kthread starved for 627 jiffies! g168597 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 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: 3409 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:__asan_memset+0x2f/0x50 mm/kasan/shadow.c:87 Code: 41 56 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 7e e4 ff ff 84 c0 74 11 4c 89 f7 89 ee 48 89 da 5b <41> 5e 5d e9 c9 b8 20 09 31 c0 5b 41 5e 5d e9 0e 77 23 09 cc 66 66 RSP: 0018:ffffc90000007430 EFLAGS: 00000202 RAX: ffff88802fc2bc01 RBX: ffffc900000074a8 RCX: ffffffff8173c426 RDX: 0000000000000060 RSI: 0000000000000000 RDI: ffffc900000074a8 RBP: 0000000000000000 R08: ffffc90000007507 R09: 1ffff92000000ea0 R10: dffffc0000000000 R11: fffff52000000ea1 R12: 0000000000000000 R13: ffff88802fc2bc80 R14: ffffc900000074a8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005632207d09b0 CR3: 0000000062c62000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x36/0x760 arch/x86/kernel/unwind_orc.c:686 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6634 [inline] kmem_cache_free+0x19b/0x690 mm/slub.c:6744 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ip6_mc_input+0x8de/0xb70 net/ipv6/ip6_input.c:593 NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6079 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6192 process_backlog+0x60e/0x14f0 net/core/dev.c:6544 __napi_poll+0xc7/0x360 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x5f7/0xdf0 net/core/dev.c:7784 handle_softirqs+0x286/0x870 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline] batadv_tt_purge+0x4d1/0x9e0 net/batman-adv/translation-table.c:3510 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3523 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245