rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=919/1/0x4000000000000000 softirq=26521/26522 fqs=19
(detected by 0, t=10502 jiffies, g=36117, q=247)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4173 Comm: syz-executor Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_release+0x77/0x870 kernel/locking/lockdep.c:5631
Code: a0 8b 48 c7 44 24 70 10 77 5c 81 4c 8d 7c 24 60 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 04 2f 66 43 c7 44 2f 09 f3 f3 <43> c6 44 2f 0b f3 0f 1f 44 00 00 65 8b 1d bf 9d a5 7e 83 fb 08 0f
RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000806
RAX: f2f2f200f1f1f1f1 RBX: 0000000000000802 RCX: 0000000000000003
RDX: ffff88807522b9b0 RSI: ffffffff8167e59d RDI: ffffffff96303820
RBP: ffffc90000dd0c50 R08: 0000000000000004 R09: 0000000000000003
R10: fffff520001ba170 R11: 1ffff920001ba170 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff96303808 R15: 1ffff920001ba174
FS: 000055557dde4500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff2252b8dac CR3: 00000000750e9000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_unlock_irqrestore+0x6d/0x100 kernel/locking/spinlock.c:194
debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline]
debug_deactivate+0x1d/0x1c0 kernel/time/hrtimer.c:471
__run_hrtimer kernel/time/hrtimer.c:1658 [inline]
__hrtimer_run_queues+0x2db/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
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:security_socket_sendmsg+0x56/0xa0 security/security.c:2252
Code: c1 e8 03 80 3c 28 00 74 08 4c 89 e7 e8 03 23 23 fe 4d 8b 24 24 4d 85 e4 74 31 4d 8d 6c 24 18 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 e0 22 23 fe 4c 89 ff 4c 89 f6 89 da 41 ff 55 00
RSP: 0018:ffffc900014dfb88 EFLAGS: 00000246
RAX: 1ffffffff177813c RBX: 00000000000000f8 RCX: ffff88807a993b80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: dffffc0000000000 R08: ffff88807a993b80 R09: 0000000000000003
R10: 000000000000000a R11: 0000000000000000 R12: ffffffff8bbc09c8
R13: ffffffff8bbc09e0 R14: ffffc900014dfc00 R15: ffff888074974200
__sock_sendmsg net/socket.c:713 [inline]
sock_write_iter+0x237/0x380 net/socket.c:1079
call_write_iter include/linux/fs.h:2172 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
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: 0033:0x7f14d9206660
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 01 af 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffcfc43ede8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000c845880 RCX: 00007f14d9206660
RDX: 00000000000000f8 RSI: 00007f14d3e78f08 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000007 R09: 00000000003ffde8
R10: cf55efc212e39634 R11: 0000000000000202 R12: 00000000000000f8
R13: 000055557ddfd290 R14: 00007ffcfc43f2b0 R15: 00007f14d3e78f08
rcu: rcu_preempt kthread starved for 10462 jiffies! g36117 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:28032 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
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:
NMI backtrace for cpu 0
CPU: 0 PID: 8294 Comm: syz.0.926 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
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:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x2c/0x60 kernel/kcov.c:206
Code: 04 24 65 48 8b 0d 94 ab 8a 7e 65 8b 15 95 ab 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c <8b> 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48
RSP: 0018:ffffc900041478f8 EFLAGS: 00000246
RAX: ffffffff816c6ba5 RBX: 0000000000000000 RCX: ffff88802c311dc0
RDX: 0000000000000000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900041479f0 R08: dffffc0000000000 R09: ffffed1017227679
R10: ffffed1017227679 R11: 1ffff11017227678 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff92000828f24
csd_lock_wait kernel/smp.c:440 [inline]
smp_call_function_single+0x225/0x490 kernel/smp.c:758
loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:723 [inline]
vmx_vcpu_load_vmcs+0x12a/0x780 arch/x86/kvm/vmx/vmx.c:1315
vmx_vcpu_load+0x1a/0x80 arch/x86/kvm/vmx/vmx.c:1380
kvm_arch_vcpu_load+0x190/0x770 arch/x86/kvm/x86.c:4385
vcpu_load+0x4e/0x80 virt/kvm/kvm_main.c:209
kvm_arch_vcpu_ioctl_run+0x53/0x1f40 arch/x86/kvm/x86.c:10337
kvm_vcpu_ioctl+0x887/0xb80 virt/kvm/kvm_main.c:3894
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
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: 0033:0x7f0c887f0be9
Code: 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 01 48
RSP: 002b:00007f0c86a37038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0c88a18090 RCX: 00007f0c887f0be9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f0c88873e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c88a18128 R14: 00007f0c88a18090 R15: 00007ffdf2b0af98