rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=a334/1/0x4000000000000000 softirq=60345/60346 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=60769, q=333 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11674 Comm: syz.5.1395 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:mark_lock+0x6/0xa20 kernel/locking/lockdep.c:4714
Code: 8e 8e e8 8d 6f 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:ffffc90000007c40 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff8880311c8bf0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8880311c8bf0 RDI: ffff8880311c8000
RBP: ffffc90000007c48 R08: 0000000000000001 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000002 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000002
FS: 00007f1d965076c0(0000) GS:ffff8881240e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f0ad556b8 CR3: 0000000076e5f000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000404
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4639 [inline]
__lock_acquire+0x10a8/0x1a40 kernel/locking/lockdep.c:5191
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:936
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:2000 [inline]
__hrtimer_run_queues+0x2e9/0x9c0 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 96 4e 45 f6 48 89 df e8 1e 9e 45 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 25 af 34 f6 65 8b 05 ee 38 94 08 85 c0 74 16 5b
RSP: 0018:ffffc90006c5f778 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff8880585ebc80 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8e15d8c3 RDI: ffffffff8c3e9b80
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888020fd4140
R13: 0000000000000246 R14: ffff8880585ebc68 R15: ffffc90006c5f8f8
spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
__skb_try_recv_datagram+0x16a/0x500 net/core/datagram.c:267
__unix_dgram_recvmsg+0x1bc/0xc30 net/unix/af_unix.c:2582
unix_dgram_recvmsg+0xcd/0x100 net/unix/af_unix.c:2681
sock_recvmsg_nosec net/socket.c:1126 [inline]
____sys_recvmsg+0x5eb/0x670 net/socket.c:2902
___sys_recvmsg+0x16a/0x1a0 net/socket.c:2946
do_recvmmsg+0x2f3/0x740 net/socket.c:3041
__sys_recvmmsg net/socket.c:3115 [inline]
__do_sys_recvmmsg net/socket.c:3138 [inline]
__se_sys_recvmmsg net/socket.c:3131 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3131
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: 0033:0x7f1d9559de59
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:00007f1d96507028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f1d95826090 RCX: 00007f1d9559de59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f1d95633e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d95826128 R14: 00007f1d95826090 R15: 00007ffeaa5d0e38
rcu: rcu_preempt kthread starved for 10502 jiffies! g60769 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:27432 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:
CPU: 1 UID: 0 PID: 11646 Comm: syz.8.1389 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+0x589/0x16c0 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 b9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90006c0f2f8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fcea8d
RDX: ffff888037950000 RSI: ffffffff81fcea67 RDI: ffff888037950000
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000000000000000(0000) GS:ffff8881241e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001880 CR3: 0000000076e5f000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000404
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
zap_pte_range mm/memory.c:1961 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x23c8/0x4a30 mm/memory.c:2109
unmap_vmas+0x299/0x5f0 mm/memory.c:2178
exit_mmap+0x1ef/0xa00 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1182
mmput+0x67/0x80 kernel/fork.c:1205
exit_mm kernel/exit.c:610 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:992
do_group_exit+0xd5/0x2a0 kernel/exit.c:1147
get_signal+0x1ec7/0x21e0 kernel/signal.c:3038
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f487c79de59
Code: Unable to access opcode bytes at 0x7f487c79de2f.
RSP: 002b:00007f487d7010e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f487ca25fa8 RCX: 00007f487c79de59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f487ca25fa8
RBP: 00007f487ca25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f487ca26038 R14: 00007fffdfd41110 R15: 00007fffdfd411f8