rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9314/1:b..l P297/1:b..l
(detected by 1, t=10502 jiffies, g=27533, q=90)
task:kworker/u4:3 state:R running task stack:22704 pid: 297 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 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 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc9000313faa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 120cb5686ed70e00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f800
RBP: ffffc9000313fbc0 R08: dffffc0000000000 R09: 1ffffffff203a618
R10: dffffc0000000000 R11: fffffbfff203a619 R12: ffffffff8c31eaa0
R13: 1ffff92000627f60 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
task:syz.6.1209 state:R running task stack:26224 pid: 9314 ppid: 8828 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:414 [inline]
loop_queue_work drivers/block/loop.c:1069 [inline]
loop_queue_rq+0x9e0/0xac0 drivers/block/loop.c:2202
__blk_mq_issue_directly block/blk-mq.c:2015 [inline]
__blk_mq_try_issue_directly+0x497/0x820 block/blk-mq.c:2071
blk_mq_try_issue_directly+0xaf/0x270 block/blk-mq.c:2102
blk_mq_submit_bio+0xfa1/0x1820 block/blk-mq.c:-1
__submit_bio+0x7d1/0x820 block/blk-core.c:917
__submit_bio_noacct_mq block/blk-core.c:997 [inline]
submit_bio_noacct+0x6b0/0x800 block/blk-core.c:1027
submit_bio+0x2c1/0x560 block/blk-core.c:1089
submit_bh fs/buffer.c:3062 [inline]
__bread_slow fs/buffer.c:1180 [inline]
__bread_gfp+0x1ae/0x380 fs/buffer.c:1384
sb_bread include/linux/buffer_head.h:337 [inline]
fat__get_entry fs/fat/dir.c:100 [inline]
fat_get_entry+0x74b/0xa60 fs/fat/dir.c:128
fat_get_short_entry fs/fat/dir.c:873 [inline]
fat_subdirs+0x113/0x220 fs/fat/dir.c:939
fat_read_root+0x5e5/0x830 fs/fat/inode.c:1413
fat_fill_super+0x3483/0x4990 fs/fat/inode.c:1863
mount_bdev+0x287/0x3c0 fs/super.c:1400
legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
vfs_get_tree+0x88/0x270 fs/super.c:1530
do_new_mount+0x24a/0xa40 fs/namespace.c:3034
do_mount fs/namespace.c:3377 [inline]
__do_sys_mount fs/namespace.c:3585 [inline]
__se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f243ed8da0a
RSP: 002b:00007f243cfe5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f243cfe5ee0 RCX: 00007f243ed8da0a
RDX: 00002000000000c0 RSI: 0000200000000040 RDI: 00007f243cfe5ea0
RBP: 00002000000000c0 R08: 00007f243cfe5ee0 R09: 0000000000000010
R10: 0000000000000010 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f243cfe5ea0 R14: 000000000000035b R15: 00002000000001c0
rcu: rcu_preempt kthread starved for 10563 jiffies! g27533 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:27800 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 9306 Comm: syz.1.1207 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x843/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4ad/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0033:0x7f83f5cb4517
Code: 8d 3d 12 8b 0b 00 e8 58 1d fa ff e8 a3 87 00 00 0f 1f 00 b8 68 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007fffd7647908 EFLAGS: 00000202
RAX: 000000000000035c RBX: 00007fffd7647a70 RCX: 00007f83f5cb4517
RDX: 00007fffd7647940 RSI: 00007fffd7647a70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00380b0c7f6b739d R09: 0000000000000000
R10: 00007fffd7647fd0 R11: 0000000000000202 R12: 00007fffd7647ff0
R13: 00007f83f5f33fac R14: 0000000000091ff3 R15: 00007fffd7647fd0
hrtimer: interrupt took 1059978728 ns