rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5616/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=73333, q=297 ncpus=2)
task:udevd state:R running task stack:24008 pid:5616 tgid:5616 ppid:4978 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
_raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:198
sock_def_readable+0x154/0x600 net/core/sock.c:3656
unix_dgram_sendmsg+0xc8f/0x1810 net/unix/af_unix.c:2292
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
sock_write_iter+0x53a/0x5b0 net/socket.c:1241
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x1f8/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb300a7407
RSP: 002b:00007ffc88082030 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdb30762880 RCX: 00007fdb300a7407
RDX: 0000000000000000 RSI: 00007ffc880820d7 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fdb307626e8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g73333 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=41586
rcu: rcu_preempt kthread starved for 10502 jiffies! g73333 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
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: 12508 Comm: syz.0.1681 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:mark_lock+0x6/0xa20 kernel/locking/lockdep.c:4714
Code: ae 8e e8 5d 5a 52 ff e9 5c fd ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 <41> 56 41 55 49 89 fd 41 54 49 89 f4 53 48 83 e4 f0 48 83 ec 70 65
RSP: 0018:ffffc90000a08c90 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880341f8ba0 RCX: 0000000000000000
RDX: 0000000000000008 RSI: ffff8880341f8ba0 RDI: ffff8880341f8000
RBP: ffffc90000a08c98 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000007
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS: 00007f200ea786c0(0000) GS:ffff888123ee8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f200ea77ff8 CR3: 00000000386bf000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: fffffffbefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x49f/0x1a40 kernel/locking/lockdep.c:5191
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:840 [inline]
advance_sched+0x718/0xd20 net/sched/sch_taprio.c:992
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 56 30 29 f6 48 89 df e8 de 7f 29 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 8f 18 f6 65 8b 05 ee 38 a7 08 85 c0 74 16 5b
RSP: 0018:ffffc900056e7b28 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffffffff9b7333d8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a3c59 RDI: ffffffff8c400f80
RBP: 0000000000000286 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffffffffffff R12: ffffffff9b733140
R13: 0000000000000005 R14: ffffc900056e7c80 R15: 7fffffffffffffff
class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline]
__do_adjtimex+0x892/0xe70 kernel/time/timekeeping.c:2953
do_adjtimex+0xa0/0x370 kernel/time/timekeeping.c:2996
do_clock_adjtime kernel/time/posix-timers.c:1169 [inline]
__do_sys_clock_adjtime+0x177/0x290 kernel/time/posix-timers.c:1181
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f200db9de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f200ea78028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131
RAX: ffffffffffffffda RBX: 00007f200de26090 RCX: 00007f200db9de59
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000
RBP: 00007f200dc33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f200de26128 R14: 00007f200de26090 R15: 00007ffe4de37828