rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1039/1:b..l P5200/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=21073, q=711 ncpus=2)
task:udevd state:R running task stack:24472 pid:5200 tgid:5200 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 41 01 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900030f72f8 EFLAGS: 00000206
RAX: c19f016bfe91ad00 RBX: 0000000000000000 RCX: c19f016bfe91ad00
RDX: 000000002a0ceb44 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffffffff81742f85 R08: ffffffff81742f85 R09: ffffffff8e13f2e0
R10: ffffc900030f74b8 R11: ffffffff81ad9d50 R12: 0000000000000002
R13: ffffffff8e13f2e0 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
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5274
skb_clone+0x212/0x3a0 net/core/skbuff.c:2087
do_one_broadcast net/netlink/af_netlink.c:1455 [inline]
netlink_broadcast_filtered+0x6ae/0x1000 net/netlink/af_netlink.c:1533
netlink_broadcast+0x37/0x50 net/netlink/af_netlink.c:1557
uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline]
kobject_uevent_net_broadcast+0x378/0x560 lib/kobject_uevent.c:410
kobject_uevent_env+0x55c/0x9f0 lib/kobject_uevent.c:608
kobject_synth_uevent+0x527/0xb00 lib/kobject_uevent.c:207
uevent_store+0x26/0x70 drivers/base/core.c:2773
kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f13322a7407
RSP: 002b:00007ffde4f74890 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f133294e880 RCX: 00007f13322a7407
RDX: 0000000000000007 RSI: 0000563985eafa00 RDI: 000000000000000c
RBP: 0000563985eafa00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000007
R13: 0000563985eb6ea0 R14: 00007f13323efea0 R15: 00007ffde4f74cb0
task:kworker/u8:5 state:R running task stack:24376 pid:1039 tgid:1039 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:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:batadv_iv_ogm_queue_add+0x0/0xd30 net/batman-adv/bat_iv_ogm.c:631
Code: f9 eb de 89 f9 80 e1 07 38 c1 0f 8c 65 ff ff ff e8 a5 e4 01 f7 e9 5b ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <55> 41 57 41 56 41 55 41 54 53 48 81 ec b8 00 00 00 44 89 4c 24 04
RSP: 0018:ffffc90003dcf870 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffffcc86 RCX: ffff88807c646800
RDX: 0000000000000034 RSI: ffff88802749a300 RDI: ffff88805cdfcdc0
RBP: ffffc90003dcf9d0 R08: ffff88807c646800 R09: 0000000000000001
R10: dffffc0000000000 R11: fffff520007b9f28 R12: ffff88807c646800
R13: ffff88807c6468a8 R14: dffffc0000000000 R15: ffff88807c646828
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:854 [inline]
batadv_iv_ogm_schedule+0xb48/0xf00 net/batman-adv/bat_iv_ogm.c:873
batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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 10533 jiffies! g21073 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
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+0x599/0xb30 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: 9543 Comm: syz.3.1753 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:ktime_get_update_offsets_now+0x3ba/0x3d0 kernel/time/timekeeping.c:2589
Code: bc e9 11 00 f3 90 44 8b 3d 53 76 ff 17 41 f6 c7 01 75 ec e8 a8 e9 11 00 e9 df fc ff ff e8 9e e9 11 00 4c 89 e8 48 83 c4 40 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 48 cd b0 09 cc 0f 1f 80 00 00 00 00
RSP: 0018:ffffc90000a08e70 EFLAGS: 00000082
RAX: 000000402d140de7 RBX: ffff8880b8728240 RCX: ffff888079a99e80
RDX: 0000000000010000 RSI: 7fffffffffffffff RDI: 000000402d140de7
RBP: ffff8880b87284a0 R08: ffffffff81afcb77 R09: ffffffff99af4508
R10: dffffc0000000000 R11: ffffffff8168e980 R12: 0000003ffff3721b
R13: 000000402d140de7 R14: ffff8880b87284a0 R15: 000000000000c9ae
FS: 00007f6afd3fe6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3bdfb7198 CR3: 00000000723b8000 CR4: 00000000003526f0
Call Trace:
hrtimer_update_base kernel/time/hrtimer.c:633 [inline]
hrtimer_interrupt+0x132/0xaa0 kernel/time/hrtimer.c:1885
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:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x58/0x340 kernel/locking/lockdep.c:5831
Code: 8b 05 7c 42 01 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 7f 42 01 11 83 f8 08 0f 83 af 01 00 00 89 c0 48 0f a3 05 a8 c1 03 0e <73> 0d e8 c1 29 09 00 84 c0 0f 84 d7 01 00 00 83 3d c2 f1 03 0e 00
RSP: 0018:ffffc9000b8978a0 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13f2e0
RBP: ffffffff81b4a6c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000ffffffff R12: 0000000000000002
R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000000
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]
futex_hash+0x5d/0x2d0 kernel/futex/core.c:308
class_hb_constructor kernel/futex/futex.h:240 [inline]
futex_wait_setup+0xc9/0x590 kernel/futex/waitwake.c:623
__futex_wait+0x148/0x3d0 kernel/futex/waitwake.c:682
futex_wait+0x104/0x360 kernel/futex/waitwake.c:715
do_futex+0x333/0x420 kernel/futex/syscalls.c:130
__do_sys_futex kernel/futex/syscalls.c:207 [inline]
__se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6afdd8f749
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:00007f6afd3fe0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f6afdfe5fa8 RCX: 00007f6afdd8f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6afdfe5fa8
RBP: 00007f6afdfe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6afdfe6038 R14: 00007fffd3326f10 R15: 00007fffd3326ff8