rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P19115/1:b..l P6039/1:b..l P8226/1:b..l P19116/1:b..l rcu: (detected by 1, t=10502 jiffies, g=86373, q=433 ncpus=2) task:dhcpcd-run-hook state:R running task stack:26648 pid:19116 tgid:19116 ppid:19066 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x4d/0x3a0 kernel/locking/lockdep.c:5879 Code: 24 28 0f 1f 44 00 00 65 8b 05 63 32 52 11 83 f8 08 0f 83 56 02 00 00 89 c0 48 0f a3 05 8c 9d 4e 0e 73 0d e8 b5 2c 09 00 84 c0 <0f> 84 94 02 00 00 83 3d c6 cf 4e 0e 00 0f 84 1c 02 00 00 65 8b 05 RSP: 0018:ffffc90003f1f0f0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff90818b01 RCX: 0000000080000001 RDX: ffffc90003f1f201 RSI: ffffffff8c0739e0 RDI: ffffffff8c0739a0 RBP: dffffc0000000000 R08: ffffc90003f1f310 R09: ffffc90003f1f2d8 R10: dffffc0000000000 R11: fffff520007e3e5d R12: ffffc90003f1f320 R13: ffffffff81759195 R14: ffffffff8e55a360 R15: ffffffff81759195 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x1aaa/0x23c0 arch/x86/kernel/unwind_orc.c:695 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3239 slab_free_hook mm/slub.c:2504 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x481/0x610 mm/slub.c:6785 exit_mmap+0x544/0xb30 mm/mmap.c:1302 __mmput+0x118/0x430 kernel/fork.c:1173 exec_mmap+0x3b4/0x440 fs/exec.c:901 begin_new_exec+0x134a/0x2460 fs/exec.c:1156 load_elf_binary+0xa47/0x2980 fs/binfmt_elf.c:1010 search_binary_handler fs/exec.c:1669 [inline] exec_binprm fs/exec.c:1701 [inline] bprm_execve+0x93d/0x1410 fs/exec.c:1753 do_execveat_common+0x50f/0x690 fs/exec.c:1859 do_execve fs/exec.c:1933 [inline] __do_sys_execve fs/exec.c:2009 [inline] __se_sys_execve fs/exec.c:2004 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2004 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f547798c107 RSP: 002b:00007ffce0a8c538 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055718cec41a8 RCX: 00007f547798c107 RDX: 000055718cebfe28 RSI: 000055718cec41a8 RDI: 000055718cebfeb0 RBP: 000055718cebfeb0 R08: 00007ffce0a8fe6b R09: 0000000000000210 R10: 0000000000000002 R11: 0000000000000246 R12: 000055718cebfe28 R13: 00007f5477b51e8b R14: 000055718cebfe28 R15: 0000000000000000 task:udevd state:R running task stack:23968 pid:8226 tgid:8226 ppid:5186 task_flags:0x20440140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7051 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] loop_queue_work drivers/block/loop.c:864 [inline] loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1911 __blk_mq_issue_directly block/blk-mq.c:2715 [inline] blk_mq_request_issue_directly+0x3bb/0x6d0 block/blk-mq.c:2802 blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2823 blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2898 blk_mq_flush_plug_list+0x456/0x570 block/blk-mq.c:2981 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1225 blk_finish_plug+0x5d/0x80 block/blk-core.c:1252 read_pages+0x3c8/0x5a0 mm/readahead.c:176 page_cache_ra_unbounded+0x74f/0x980 mm/readahead.c:302 do_page_cache_ra mm/readahead.c:332 [inline] force_page_cache_ra mm/readahead.c:361 [inline] page_cache_sync_ra+0x433/0xc40 mm/readahead.c:579 filemap_get_pages+0x4c5/0x1ec0 mm/filemap.c:2690 filemap_read+0x447/0x1230 mm/filemap.c:2800 blkdev_read_iter+0x30a/0x440 block/fops.c:856 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x582/0xa70 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbcbd0a7407 RSP: 002b:00007ffdccf720e0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fbcbd80b880 RCX: 00007fbcbd0a7407 RDX: 0000000000000200 RSI: 00007fbcbd7ff000 RDI: 0000000000000008 RBP: 0000556de1650f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 000000000138b800 R14: 0000556de16568f8 R15: 00007fbcbd93239c task:kworker/u8:11 state:R running task stack:20328 pid:6039 tgid:6039 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:deref_stack_reg+0x1b3/0x230 arch/x86/kernel/unwind_orc.c:422 Code: 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 11 08 00 00 49 89 c6 48 8b 5c 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 03 0f b7 00 4c 89 33 b0 01 eb 02 31 c0 48 83 c4 RSP: 0018:ffffc90004dff1a0 EFLAGS: 00000246 RAX: 1ffff920009bfe6d RBX: ffffc90004dff368 RCX: 0000000000000001 RDX: ffffc90004dff368 RSI: dffffc0000000000 RDI: ffffc90004dff318 RBP: 1ffff920009bfe65 R08: ffffc90004dff318 R09: ffffc90004dff378 R10: dffffc0000000000 R11: fffff520009bfe71 R12: 1ffff920009bfe66 R13: 1ffff920009bfe67 R14: ffffc90004dff3b0 R15: dffffc0000000000 unwind_next_frame+0x18c6/0x23c0 arch/x86/kernel/unwind_orc.c:-1 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780 kmalloc_noprof include/linux/slab.h:957 [inline] batadv_forw_packet_alloc+0x1e9/0x390 net/batman-adv/send.c:506 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:570 [inline] batadv_iv_ogm_queue_add+0x85f/0xd30 net/batman-adv/bat_iv_ogm.c:677 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:841 [inline] batadv_iv_ogm_schedule+0x874/0xf50 net/batman-adv/bat_iv_ogm.c:873 batadv_iv_send_outstanding_bat_ogm_packet+0x6c8/0x7e0 net/batman-adv/bat_iv_ogm.c:1709 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 task:syz.5.2458 state:R running task stack:24960 pid:19115 tgid:19104 ppid:18239 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:memset+0xf/0x20 arch/x86/lib/memset_64.S:38 Code: 44 88 1f e9 6e 1d 79 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 e9 42 1d 79 f5 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000449e7d0 EFLAGS: 00000202 RAX: ffffc9000449e900 RBX: ffffc9000449e8e0 RCX: 000000000000000f RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc9000449e8f9 RBP: dffffc0000000000 R08: ffffc9000449e907 R09: ffffc9000449e8f8 R10: dffffc0000000000 R11: fffff52000893d21 R12: ffffc9000449e8f8 R13: 1ffff92000893d17 R14: ffffc9000449e8a8 R15: ffffc9000449e8f0 unwind_next_frame+0xeae/0x23c0 arch/x86/kernel/unwind_orc.c:607 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x1be/0x650 mm/slub.c:6882 tipc_dest_pop+0x19c/0x230 net/tipc/name_table.c:1180 tipc_sk_mcast_rcv+0x5a6/0xf30 net/tipc/socket.c:1244 tipc_mcast_xmit+0x1385/0x19e0 net/tipc/bcast.c:424 tipc_send_group_bcast+0x80d/0xad0 net/tipc/socket.c:1130 __tipc_sendmsg+0x33b/0x2ba0 net/tipc/socket.c:1432 tipc_sendmsg+0x55/0x70 net/tipc/socket.c:1399 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2735 __do_sys_sendmmsg net/socket.c:2762 [inline] __se_sys_sendmmsg net/socket.c:2759 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6b9999aeb9 RSP: 002b:00007f6b9a7e5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f6b99c16090 RCX: 00007f6b9999aeb9 RDX: 0400000000000181 RSI: 00002000000030c0 RDI: 0000000000000003 RBP: 00007f6b99a08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 9200000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6b99c16128 R14: 00007f6b99c16090 R15: 00007ffe76b87908 rcu: rcu_preempt kthread starved for 10690 jiffies! g86373 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:27808 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 19092 Comm: syz.9.2454 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x4d/0x3a0 kernel/locking/lockdep.c:5879 Code: 24 28 0f 1f 44 00 00 65 8b 05 63 32 52 11 83 f8 08 0f 83 56 02 00 00 89 c0 48 0f a3 05 8c 9d 4e 0e 73 0d e8 b5 2c 09 00 84 c0 <0f> 84 94 02 00 00 83 3d c6 cf 4e 0e 00 0f 84 1c 02 00 00 65 8b 05 RSP: 0018:ffffc90000007c00 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000086 RCX: 0000000080010003 RDX: 0000000000010000 RSI: ffffffff8c0739e0 RDI: ffffffff8c0739a0 RBP: 0000000000000001 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e R10: dffffc0000000000 R11: fffffbfff1fde36f R12: dffffc0000000000 R13: ffffffff818948a6 R14: ffff88802f874a18 R15: ffffffff81894483 FS: 00007fe2f63f66c0(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbcbd800000 CR3: 00000000550d7000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1b/0x80 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] unlock_task_sighand include/linux/sched/signal.h:756 [inline] posixtimer_send_sigqueue+0x486/0xa70 kernel/signal.c:2084 posix_timer_queue_signal kernel/time/posix-timers.c:364 [inline] posix_timer_fn+0x121/0x1c0 kernel/time/posix-timers.c:379 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x527/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3d0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:gup_fast_fallback+0x1d04/0x22e0 mm/gup.c:3214 Code: ff 48 63 9c 24 3c 01 00 00 41 81 fc 00 00 10 00 41 0f 92 c6 48 89 df 4c 8b ac 24 c8 00 00 00 4c 89 ee e8 5f 7c b4 ff 49 29 dd <0f> 95 c0 41 84 c6 75 0a e8 ef 79 b4 ff e9 a1 00 00 00 49 89 de 49 RSP: 0018:ffffc90003caf6e0 EFLAGS: 00000246 RAX: ffffffff820ffd51 RBX: 0000000000000001 RCX: ffff888032ea8000 RDX: 0000000000000002 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc90003caf8d0 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e R10: dffffc0000000000 R11: fffffbfff1fde36f R12: 0000000000000003 R13: 0000000000000000 R14: 0000200000049001 R15: ffff8880859c4000 get_futex_key+0x962/0x1690 kernel/futex/core.c:638 futex_wait_requeue_pi+0x2bf/0x960 kernel/futex/requeue.c:808 do_futex+0x181/0x420 kernel/futex/syscalls.c:153 __do_sys_futex kernel/futex/syscalls.c:207 [inline] __se_sys_futex+0x3a8/0x450 kernel/futex/syscalls.c:188 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe2f819aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe2f63f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fe2f8415fa0 RCX: 00007fe2f819aeb9 RDX: 0000000000000000 RSI: 000080000000000b RDI: 000020000000cffc RBP: 00007fe2f8208c1f R08: 0000200000048000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe2f8416038 R14: 00007fe2f8415fa0 R15: 00007ffe125af968 raw-gadget.0 gadget.9: ignoring, device is not running