rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5431/1:b..l P4422/1:b..l
(detected by 1, t=10503 jiffies, g=16117, q=148 ncpus=2)
task:kworker/u4:11 state:R running task stack:21960 pid:4422 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90004a87920 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 8d599fb10a576f00
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760
RBP: ffffc90004a87a28 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: 1ffff92000950f30 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline]
batadv_iv_ogm_schedule+0x413/0xe90 net/batman-adv/bat_iv_ogm.c:868
batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
task:syz-executor state:R running task stack:23952 pid:5431 ppid:4254 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000494f860 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 617d7db4c2ec0b00
RDX: 0000000000000000 RSI: ffffffff8a8c1700 RDI: ffffffff8adef760
RBP: ffffc9000494f968 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: 1ffff92000929f18 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
page_ext_get+0x3a/0x2a0 mm/page_ext.c:157
__set_page_owner+0x24/0x60 mm/page_owner.c:192
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
__alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
vm_area_alloc_pages mm/vmalloc.c:3002 [inline]
__vmalloc_area_node mm/vmalloc.c:3071 [inline]
__vmalloc_node_range+0x959/0x1390 mm/vmalloc.c:3243
vmalloc_user+0x70/0x80 mm/vmalloc.c:3397
kcov_ioctl+0x54/0x640 kernel/kcov.c:713
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff68b18f34b
RSP: 002b:00007ffdab36e0a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007ff68b18f34b
RDX: 0000000000080000 RSI: ffffffff80086301 RDI: 00000000000000de
RBP: 00007ff68b3e65d8 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 00007ffdab36e3e8 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10517 jiffies! g16117 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:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5452 Comm: syz.0.304 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:preempt_count_sub+0x33/0x160 kernel/sched/core.c:5737
Code: fc ff df 48 c7 c0 40 91 be 96 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 83 3d 56 d9 66 15 00 75 25 65 8b 05 55 b7 aa 7e <89> c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 ff ff 00 00 00 0f 93 c1 84
RSP: 0018:ffffc90004b8f9e8 EFLAGS: 00000046
RAX: 0000000080000001 RBX: dffffc0000000000 RCX: ffffffff96be9103
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc90004b8fa90 R08: dffffc0000000000 R09: ffffed102802f381
R10: ffffed102802f381 R11: 1ffff1102802f380 R12: ffffffff812f3fc0
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000971f40
FS: 00007fd6081af6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c336701 CR3: 0000000076097000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__local_bh_enable_ip+0x125/0x1b0 kernel/softirq.c:424
local_bh_enable include/linux/bottom_half.h:33 [inline]
fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline]
copy_fpstate_to_sigframe+0x52d/0xcb0 arch/x86/kernel/fpu/signal.c:233
get_sigframe arch/x86/kernel/signal.c:297 [inline]
__setup_rt_frame arch/x86/kernel/signal.c:472 [inline]
setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
handle_signal arch/x86/kernel/signal.c:828 [inline]
arch_do_signal_or_restart+0x622/0x1240 arch/x86/kernel/signal.c:873
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd60738f749
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:00007fd6081af0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fd6075e6098 RCX: 00007fd60738f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd6075e6098
RBP: 00007fd6075e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd6075e6128 R14: 00007ffff163a360 R15: 00007ffff163a448