rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5997/1:b..l rcu: (detected by 0, t=10503 jiffies, g=18705, q=909 ncpus=2) task:kworker/u8:13 state:R running task stack:21832 pid:5997 tgid:5997 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound cfg80211_wiphy_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 20 b1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 20 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 da 50 72 ff cc 48 8d 3d 37 78 e7 RSP: 0018:ffffc900045bf3d8 EFLAGS: 00000286 RAX: 34d6cff9ed99fd00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000004933f4aa RSI: ffffffff8d976049 RDI: ffffffff8bc08360 RBP: ffffffff8173fd65 R08: ffffffff8173fd65 R09: ffffffff8df41aa0 R10: dffffc0000000000 R11: ffffffff81acf3d0 R12: 0000000000000002 R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 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:6670 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6781 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1234 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ieee80211_iface_work+0xb2a/0x12d0 net/mac80211/iface.c:1792 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread starved for 10348 jiffies! g18705 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 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+0x510/0xa50 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7118 Comm: syz.5.222 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:tk_clock_read kernel/time/timekeeping.c:293 [inline] RIP: 0010:__timekeeping_advance+0x53/0x10d0 kernel/time/timekeeping.c:2333 Code: 00 85 ed 0f 85 6f 0c 00 00 49 8d af 50 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 e9 48 c1 e9 03 48 89 4c 24 70 80 3c 01 00 <74> 08 48 89 ef e8 63 c1 77 00 4c 8b 75 00 4c 89 f0 48 c1 e8 03 48 RSP: 0018:ffffc90000a08b10 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffffffff331f2ca RDX: ffff88802f6f5b80 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff998f9650 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000141170 R12: ffff8880b8728ba0 R13: 000000472d241719 R14: 0000000000000006 R15: ffffffff998f9500 FS: 00007f1d515d26c0(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000054c0 CR3: 00000000223b7000 CR4: 0000000000350ef0 Call Trace: timekeeping_advance kernel/time/timekeeping.c:2385 [inline] update_wall_time+0x31/0x200 kernel/time/timekeeping.c:2395 tick_sched_do_timer kernel/time/tick-sched.c:253 [inline] tick_nohz_handler+0xf5/0x710 kernel/time/tick-sched.c:312 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4d0/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 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:__refcount_add include/linux/refcount.h:290 [inline] RIP: 0010:__refcount_inc include/linux/refcount.h:366 [inline] RIP: 0010:refcount_inc include/linux/refcount.h:383 [inline] RIP: 0010:wait_for_commit+0x370/0x440 fs/btrfs/transaction.c:940 Code: 00 f0 45 0f c1 6f e8 31 ff 44 89 ee e8 39 ff f0 fd 45 85 ed 74 31 bf fe ff ff 7f 44 89 ee e8 27 ff f0 fd 41 81 fd fe ff ff 7f <77> 27 e8 d9 fa f0 fd 48 8b 7c 24 28 e8 7f 3a 8c 07 b0 01 48 89 44 RSP: 0018:ffffc900030e73a0 EFLAGS: 00000293 RAX: ffffffff83cffcd9 RBX: ffff888034b1a000 RCX: 0000000000000002 RDX: ffff88802f6f5b80 RSI: 0000000000000005 RDI: 000000007ffffffe RBP: ffffc900030e74d0 R08: ffff888034b1a013 R09: 1ffff11006963402 R10: dffffc0000000000 R11: ffffed1006963403 R12: dffffc0000000000 R13: 0000000000000005 R14: ffff888034b1a010 R15: ffff888034b1a028 btrfs_commit_transaction+0x47a/0x3b10 fs/btrfs/transaction.c:2281 prepare_to_relocate+0x39f/0x490 fs/btrfs/relocation.c:3479 relocate_block_group+0x132/0xd70 fs/btrfs/relocation.c:3504 btrfs_relocate_block_group+0x6b6/0xc70 fs/btrfs/relocation.c:3966 btrfs_relocate_chunk+0x12f/0x5c0 fs/btrfs/volumes.c:3424 __btrfs_balance+0x18ff/0x24e0 fs/btrfs/volumes.c:4197 btrfs_balance+0xac2/0x11b0 fs/btrfs/volumes.c:4571 btrfs_ioctl_balance+0x3d3/0x610 fs/btrfs/ioctl.c:3525 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d5078f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1d515d2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1d509e6090 RCX: 00007f1d5078f749 RDX: 0000200000000180 RSI: 00000000c4009420 RDI: 0000000000000007 RBP: 00007f1d50813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1d509e6128 R14: 00007f1d509e6090 R15: 00007ffe03ae9858