rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4486/1:b..l P12299/1:b..l P4177/1:b..l
(detected by 0, t=10502 jiffies, g=51549, q=52)
task:udevd state:R running task stack:23840 pid: 4177 ppid: 3562 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 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:link_path_walk+0x4b8/0xd40 fs/namei.c:2273
Code: 04 28 84 c0 0f 85 73 04 00 00 80 22 fb 4c 89 e0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 80 04 00 00 41 8b 1c 24 89 de 83 e6 01 <31> ff e8 21 5f ad ff f6 c3 01 0f 85 56 02 00 00 e8 b3 5b ad ff 45
RSP: 0018:ffffc90002e9fa60 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000200000 RCX: ffff88807aa95940
RDX: ffffc90002e9fc9c RSI: 0000000000000000 RDI: 000000000000002e
RBP: ffffc90002e9fb88 R08: ffff88807aa95940 R09: 0000000000000002
R10: 000000000000002f R11: 0000000000000000 R12: ffff888147d7e000
R13: dffffc0000000000 R14: 00000003b9202150 R15: ffffc90002e9fc70
path_lookupat+0x9d/0x440 fs/namei.c:2462
filename_lookup+0x1e2/0x4f0 fs/namei.c:2492
user_path_at_empty+0x40/0x190 fs/namei.c:2891
do_readlinkat+0xd4/0x480 fs/stat.c:442
__do_sys_readlink fs/stat.c:475 [inline]
__se_sys_readlink fs/stat.c:472 [inline]
__x64_sys_readlink+0x7b/0x90 fs/stat.c:472
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: 0033:0x7f4408a1b3a7
RSP: 002b:00007ffc31af0c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 000055e9d646ba10 RCX: 00007f4408a1b3a7
RDX: 0000000000000400 RSI: 00007ffc31af1150 RDI: 000055e9d646ba10
RBP: 000055e9d646ba2d R08: 0000000000007890 R09: 0000000000000002
R10: 0000000000000100 R11: 0000000000000246 R12: 00007ffc31af1150
R13: 00007ffc31af0d50 R14: 000055e9b21776d7 R15: 00007ffc31af1de0
task:syz.7.2312 state:R running task stack:27520 pid:12299 ppid: 11873 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:check_region_inline mm/kasan/generic.c:172 [inline]
RIP: 0010:kasan_check_range+0x23/0x290 mm/kasan/generic.c:189
Code: 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 a4 01 00 00 41 57 41 56 53 49 89 f8 49 01 f0 0f 82 57 02 00 00 49 89 f8 49 c1 e8 2f <41> 81 f8 ff ff 01 00 0f 82 43 02 00 00 49 bf 01 00 00 00 00 fc ff
RSP: 0018:ffffc900037efd80 EFLAGS: 00000a07
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815bf92b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d699a68
RBP: ffffc900037efec0 R08: 000000000001ffff R09: 0000000000000000
R10: fffffbfff1ad334e R11: 1ffffffff1ad334d R12: ffffffff8c11c720
R13: 1ffff920006fdfc0 R14: 0000000000000000 R15: dffffc0000000000
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
cpumask_test_cpu include/linux/cpumask.h:344 [inline]
cpu_online include/linux/cpumask.h:895 [inline]
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0xbb/0x3f0 kernel/locking/lockdep.c:5594
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__task_pid_nr_ns+0x21/0x420 kernel/pid.c:497
task_tgid_vnr include/linux/sched.h:1585 [inline]
__ia32_sys_getpid+0x19/0x20 kernel/sys.c:945
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: 0033:0x7fc67910be67
RSP: 002b:00007ffffae28488 EFLAGS: 00000206 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007ffffae285f0 RCX: 00007fc67910be67
RDX: 00007ffffae284c0 RSI: 00007ffffae285f0 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0008a61a42d4ce2b
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000744a8
R13: 00007fc67936c090 R14: ffffffffffffffff R15: 00007ffffae28bd0
task:kworker/u4:11 state:R running task stack:23264 pid: 4486 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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:ffffc900032dfaa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0630d8628c855400
RDX: 0000000000000000 RSI: ffffffff8a0b2b40 RDI: ffffffff8a59a880
RBP: ffffc900032dfbc0 R08: dffffc0000000000 R09: fffffbfff1ff7a19
R10: fffffbfff1ff7a19 R11: 1ffffffff1ff7a18 R12: ffffffff8c11c720
R13: 1ffff9200065bf60 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+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10582 jiffies! g51549 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:27848 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12300 Comm: syz.7.2312 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3682 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3701 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3756 [inline]
RIP: 0010:__lock_acquire+0x16d8/0x7c60 kernel/locking/lockdep.c:5012
Code: 00 48 8b 7c 24 38 48 8b 74 24 10 48 ba 00 00 00 00 00 fc ff df e9 65 ff ff ff 4c 8d 73 18 4c 89 f0 48 c1 e8 03 42 80 3c 00 00 <74> 12 4c 89 f7 e8 de 1d 60 00 49 b8 00 00 00 00 00 fc ff df 49 8b
RSP: 0018:ffffc90000dd08e0 EFLAGS: 00000046
RAX: 1ffffffff1ff7d87 RBX: ffffffff8ffbec20 RCX: ffffffff815c1100
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbd0c8
RBP: ffffc90000dd0b30 R08: dffffc0000000000 R09: fffffbfff1ff7a1a
R10: fffffbfff1ff7a1a R11: 1ffffffff1ff7a19 R12: 4b21b045db16ba9e
R13: ffff888022b13b80 R14: ffffffff8ffbec38 R15: ffff888022b14690
FS: 00007fc67737c6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000024a9b000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1689 [inline]
__hrtimer_run_queues+0x5ff/0xc40 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 5e bd a9 f7 48 89 df e8 26 92 aa f7 e8 c1 2b cb f7 fb bf 01 00 00 00 76 b5 9e f7 65 8b 05 07 b3 4f 76 85 c0 74 02 5b c3 e8 b4 bd 4d
RSP: 0018:ffffc90003c47bc0 EFLAGS: 00000282
RAX: 6593f82a924ead00 RBX: ffff888029e85c80 RCX: 6593f82a924ead00
RDX: dffffc0000000000 RSI: ffffffff8a0b18a0 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10053d0b91
R10: ffffed10053d0b91 R11: 1ffff110053d0b90 R12: ffff888029e85c80
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
spin_unlock_irq include/linux/spinlock.h:414 [inline]
get_signal+0x11d6/0x12c0 kernel/signal.c:2903
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc679114fc7
Code: ff ff 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
RSP: 002b:00007fc67737c038 EFLAGS: 00000246
RAX: 0000000000000113 RBX: 00007fc67936bfa0 RCX: 00007fc679114fc9
RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007fc679197f91 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc67936c038 R14: 00007fc67936bfa0 R15: 00007ffffae28958