rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20257/3:b..l P12/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=82513, q=243 ncpus=2)
task:kworker/u8:0 state:R running task stack:22264 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline]
RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x3b/0x350 kernel/locking/lockdep.c:5831
Code: 89 d5 41 54 45 89 c4 55 89 cd 53 48 89 fb 48 83 ec 38 65 48 8b 05 bd e6 3e 12 48 89 44 24 30 31 c0 66 90 65 8b 05 d9 e6 3e 12 <83> f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 a2 13 0f 0f 82 74
RSP: 0018:ffffc90000117a40 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8e5c1260 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e5c1260
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_process_nc_paths.part.0+0xe4/0x3e0 net/batman-adv/network-coding.c:687
batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline]
batadv_nc_worker+0xcd3/0x1030 net/batman-adv/network-coding.c:728
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:syz.0.2949 state:R running task stack:26312 pid:20257 tgid:20256 ppid:5843 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
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]
filemap_map_pages+0xe15/0x1670 mm/filemap.c:3791
do_fault_around mm/memory.c:5531 [inline]
do_read_fault mm/memory.c:5564 [inline]
do_fault mm/memory.c:5707 [inline]
do_pte_missing+0xe36/0x3ba0 mm/memory.c:4234
handle_pte_fault mm/memory.c:6052 [inline]
__handle_mm_fault+0x152a/0x2a50 mm/memory.c:6195
handle_mm_fault+0x589/0xd10 mm/memory.c:6364
faultin_page mm/gup.c:1144 [inline]
__get_user_pages+0x551/0x34a0 mm/gup.c:1446
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1880
__mm_populate+0x1d8/0x380 mm/gup.c:1983
mm_populate include/linux/mm.h:3367 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:585
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f057678ebe9
RSP: 002b:00007f0577571038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f05769c5fa0 RCX: 00007f057678ebe9
RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f0576811e19 R08: ffffffffffffffff R09: 0000000094eb2000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f05769c6038 R14: 00007f05769c5fa0 R15: 00007fff1cf84f78
rcu: rcu_preempt kthread timer wakeup didn't happen for 10551 jiffies! g82513 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=129741
rcu: rcu_preempt kthread starved for 10557 jiffies! g82513 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 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: 1 UID: 0 PID: 1297 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 26 be 00 f6 48 89 df e8 0e 12 01 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 0e f1 f5 65 8b 05 be ab 3f 08 85 c0 74 16 5b
RSP: 0000:ffffc900048bf978 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9b115ba0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8de522e8 RDI: ffffffff8c162d80
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90ab6b97 R11: 0000000000000000 R12: ffffffff9b115ca8
R13: 0000000000000003 R14: 0000000000000001 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff8881247b5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000a5030 CR3: 000000004f227000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: 0000000000000002 DR2: 0000000000000008
DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline]
uart_port_unlock_deref drivers/tty/serial/serial_core.c:88 [inline]
uart_write+0x4c1/0xb30 drivers/tty/serial/serial_core.c:629
handle_tx+0x204/0x630 drivers/net/caif/caif_serial.c:222
__netdev_start_xmit include/linux/netdevice.h:5222 [inline]
netdev_start_xmit include/linux/netdevice.h:5231 [inline]
xmit_one net/core/dev.c:3839 [inline]
dev_hard_start_xmit+0x94/0x740 net/core/dev.c:3855
__dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4725
dev_queue_xmit include/linux/netdevice.h:3361 [inline]
tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245