rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=f5f4/1/0x4000000000000000 softirq=23734/23734 fqs=1
rcu: (detected by 1, t=10505 jiffies, g=18573, q=999 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6712 Comm: syz.3.173 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_is_held_type+0x1e/0x140 kernel/locking/lockdep.c:5933
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 0d 1a bc 4d 05 b8 ff ff ff ff 85 c9 0f 84 ed 00 00 00 65 8b 15 aa 46 80 08 <85> d2 0f 85 de 00 00 00 41 57 41 56 41 55 41 54 55 53 48 83 ec 08
RSP: 0018:ffffc90000007dd0 EFLAGS: 00000002
RAX: 00000000ffffffff RBX: ffff888054351300 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8880543512c0
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888054351300
R13: ffff88802bf455f8 R14: dffffc0000000000 R15: ffff8880b8428750
FS: 00007f5fbc21e6c0(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0cbc3e8158 CR3: 0000000077ead000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0x838/0xd20 net/sched/sch_taprio.c:933
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
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 d6 0e 58 f6 48 89 df e8 ae 5e 58 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 b5 2a 48 f6 65 8b 05 6e 0d 7d 08 85 c0 74 16 5b
RSP: 0018:ffffc900053ff750 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff888036080f80 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8df0fe0d RDI: ffffffff8c1c4780
RBP: 0000000000000202 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888036080f80
R13: 0000000000000202 R14: 0000000000000001 R15: ffffffff81e1125d
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
prepare_to_wait_exclusive+0xdc/0x2c0 kernel/sched/wait.c:275
unix_wait_for_peer+0xca/0x2a0 net/unix/af_unix.c:1613
unix_dgram_sendmsg+0x1696/0x1810 net/unix/af_unix.c:2261
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2699
___sys_sendmsg+0x190/0x1e0 net/socket.c:2753
__sys_sendmmsg+0x205/0x430 net/socket.c:2842
__do_sys_sendmmsg net/socket.c:2869 [inline]
__se_sys_sendmmsg net/socket.c:2866 [inline]
__x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2866
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: 0033:0x7f5fbb39ce59
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:00007f5fbc21e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f5fbb615fa0 RCX: 00007f5fbb39ce59
RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f5fbb432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5fbb616038 R14: 00007f5fbb615fa0 R15: 00007ffe5a0ab9a8
rcu: rcu_preempt kthread starved for 10500 jiffies! g18573 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:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
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:
CPU: 1 UID: 0 PID: 5616 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 83 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0018:ffffc9000396f618 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fc2dfd
RDX: ffff88807e1ca540 RSI: ffffffff81fc2dd7 RDI: ffff88807e1ca540
RBP: ffff8880b8443560 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886ad R14: 0000000000000001 R15: ffff8880b853c800
FS: 0000555569301500(0000) GS:ffff888124487000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff8ad3ea2f8 CR3: 000000005b0de000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
dup_mmap+0x1307/0x21b0 mm/mmap.c:1905
dup_mm kernel/fork.c:1534 [inline]
copy_mm kernel/fork.c:1586 [inline]
copy_process+0x6c78/0x7ed0 kernel/fork.c:2264
kernel_clone+0x176/0x9e0 kernel/fork.c:2722
__do_sys_clone+0xd9/0x120 kernel/fork.c:2863
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: 0033:0x7f0cbc1c58d2
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd3fba1b10 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd3fba1b10 RCX: 00007f0cbc1c58d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd3fba1c9c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555693017d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000021b22 R15: 00007ffd3fba1cf0