rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (4 ticks this GP) idle=252c/1/0x4000000000000000 softirq=114742/114742 fqs=17
rcu: (detected by 0, t=10502 jiffies, g=117009, q=704 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 22102 Comm: syz.1.4679 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+0x1/0x190 kernel/locking/lockdep.c:4714
Code: 0f b9 3a 90 41 89 e9 48 89 df 48 8b 2c 24 e9 b6 fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83 f9
RSP: 0018:ffffc90000a08bd0 EFLAGS: 00000046
RAX: 00000000000c40cf RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff888020b6c9c8 RDI: ffff888020b6be00
RBP: 0000000000000000 R08: ffffffff81b31166 R09: 0000000000080000
R10: 0000000000000000 R11: ffff8880b87281d8 R12: ffffffffffffff02
R13: ffff888020b6c9c8 R14: ffff888020b6be00 R15: 0000000000000000
FS: 00007ff3f9e746c0(0000) GS:ffff888125059000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f55c25e5eb8 CR3: 0000000032ab7000 CR4: 0000000000350ef0
Call Trace:
mark_usage kernel/locking/lockdep.c:4639 [inline]
__lock_acquire+0x63a/0x2cf0 kernel/locking/lockdep.c:5191
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:174
__run_hrtimer kernel/time/hrtimer.c:2036 [inline]
__hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:arch_atomic64_read arch/x86/include/asm/atomic64_64.h:15 [inline]
RIP: 0010:raw_atomic64_read include/linux/atomic/atomic-arch-fallback.h:2583 [inline]
RIP: 0010:raw_atomic_long_read include/linux/atomic/atomic-long.h:38 [inline]
RIP: 0010:atomic_long_read include/linux/atomic/atomic-instrumented.h:3189 [inline]
RIP: 0010:__mutex_trylock_common+0x8c/0x270 kernel/locking/mutex.c:89
Code: f1 f1 f8 f3 f3 f3 49 89 44 1d 00 41 c6 44 1d 04 00 65 48 8b 05 2d df ca 11 48 89 04 24 be 08 00 00 00 e8 77 70 92 00 4c 89 f0 <48> c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 f2 6d 92 00 48 8d 5c 24
RSP: 0018:ffffc900100474c0 EFLAGS: 00000256
RAX: ffff88803392b010 RBX: dffffc0000000000 RCX: ffffffff81a190e9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88803392b010
RBP: ffffc90010047570 R08: ffff88803392b017 R09: 1ffff11006725602
R10: dffffc0000000000 R11: ffffed1006725603 R12: ffff88803392b010
R13: 1ffff92002008e9c R14: ffff88803392b010 R15: 0000000000000000
__mutex_trylock kernel/locking/mutex.c:134 [inline]
__mutex_lock_common kernel/locking/mutex.c:649 [inline]
__mutex_lock+0x1b8/0x1550 kernel/locking/mutex.c:821
__unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2579
sock_recvmsg_nosec+0x130/0x170 net/socket.c:1126
____sys_recvmsg+0x3e3/0x4a0 net/socket.c:2902
___sys_recvmsg+0x213/0x5a0 net/socket.c:2946
do_recvmmsg+0x31a/0x7f0 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+0x198/0x250 net/socket.c:3131
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3f8f9de59
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:00007ff3f9e74028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007ff3f9226090 RCX: 00007ff3f8f9de59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007ff3f9033e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3f9226128 R14: 00007ff3f9226090 R15: 00007ffcbcbfe9f8
rcu: rcu_preempt kthread starved for 10468 jiffies! g117009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 0 UID: 0 PID: 22098 Comm: syz.8.4676 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:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x10b5/0x14b0 kernel/smp.c:892
Code: 1e 89 de 83 e6 01 31 ff e8 d8 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1a 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1a 0c 00 eb e5 44 89
RSP: 0018:ffffc900047371a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888020fddd00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900047372c8 R08: ffff88801227d887 R09: 1ffff1100244fb10
R10: dffffc0000000000 R11: ffffffff8178e3f0 R12: 1ffff110170e81d1
R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124f59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3f6032 CR3: 0000000064942000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 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+0x5c4/0x1090 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]
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+0x3ef5/0x4f10 mm/memory.c:2109
unmap_vmas+0x390/0x550 mm/memory.c:2178
exit_mmap+0x293/0x9f0 mm/mmap.c:1300
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:610
do_exit+0x6cd/0x2360 kernel/exit.c:992
do_group_exit+0x22d/0x2f0 kernel/exit.c:1147
get_signal+0x121b/0x12c0 kernel/signal.c:3038
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x104/0x730 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+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f184519de59
Code: Unable to access opcode bytes at 0x7f184519de2f.
RSP: 002b:00007f18460cc0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f1845426188 RCX: 00007f184519de59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1845426188
RBP: 00007f1845426180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1845426218 R14: 00007fff0f052980 R15: 00007fff0f052a68