rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=4b54/1/0x4000000000000000 softirq=34890/34890 fqs=21
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5608/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=41665, q=129 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9589 Comm: syz.2.1090 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3820 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline]
RIP: 0010:__lock_acquire+0x82c/0x1a40 kernel/locking/lockdep.c:5237
Code: 89 de 48 89 ef e8 84 eb ff ff 85 c0 0f 85 7b fc ff ff e9 77 fb ff ff 0f b7 43 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 c4 67 85 14 <0f> 83 b2 09 00 00 49 be eb 83 b5 80 46 86 c8 61 48 8b 4c 24 08 4c
RSP: 0018:ffffc90000007d48 EFLAGS: 00000007
RAX: 0000000000000071 RBX: ffff88807f4a30e0 RCX: 0000000000000000
RDX: 00000000ffe2f3a6 RSI: 0000000010f50544 RDI: 000000009dc59b3c
RBP: ffff88807f4a2540 R08: 00000000ffffffff R09: 0000000000000071
R10: 0000000000000000 R11: 0000000000000000 R12: bc101d9a73125dae
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f54bbdb46c0(0000) GS:ffff888123dd8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3350cff8 CR3: 0000000058f1f000 CR4: 00000000003526f0
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174
__run_hrtimer kernel/time/hrtimer.c:2036 [inline]
__hrtimer_run_queues+0x1b7/0x9c0 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 f6 d0 27 f6 48 89 df e8 7e 20 28 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 05 2e 17 f6 65 8b 05 4e 57 a6 08 85 c0 74 16 5b
RSP: 0018:ffffc9000f497d78 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9b7433d8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a8186 RDI: ffffffff8c402680
RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffffffffffff R12: 1ffff92001e92fb6
R13: 000000000cc45eb3 R14: 000000000cc45eb3 R15: 0000000000000000
class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline]
do_settimeofday64+0x326/0x4d0 kernel/time/timekeeping.c:1665
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123
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: 0033:0x7f54bdb9e019
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:00007f54bbdb4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f54bde26180 RCX: 00007f54bdb9e019
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f54bdc3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54bde26218 R14: 00007f54bde26180 R15: 00007ffd3021a2d8
task:syz-executor state:R running task stack:23064 pid:5608 tgid:5608 ppid:5604 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 include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
copy_pte_range mm/memory.c:1347 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c1f/0x5b20 mm/memory.c:1555
dup_mmap+0xd44/0x21b0 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4588/0x8030 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
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: 0033:0x7f52d31c6a92
RSP: 002b:00007ffd109442a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd109442a0 RCX: 00007f52d31c6a92
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd1094442c R08: 0000000000000000 R09: 0000000000000001
R10: 000055557d0307d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 000000000004dbc6 R15: 00007ffd10944480
rcu: rcu_preempt kthread starved for 10460 jiffies! g41665 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: 9578 Comm: syz.0.1093 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x58e/0x1870 kernel/smp.c:912
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 c4 9b 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31
RSP: 0018:ffffc9000f827268 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc900053a9000
RDX: 0000000000080000 RSI: ffffffff81fdc91c RDI: ffff888029102540
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 00007f5da43046c0(0000) GS:ffff888123ed8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000292030 CR3: 000000002a7bb000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077
__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
flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline]
ptep_clear_flush+0x148/0x170 mm/pgtable-generic.c:104
wp_page_copy mm/memory.c:3941 [inline]
do_wp_page+0x12a4/0x4350 mm/memory.c:4336
handle_pte_fault mm/memory.c:6395 [inline]
__handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6517
handle_mm_fault+0x37b/0xa30 mm/memory.c:6686
do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1394
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0010:__put_user_nocheck_4+0x3/0x20 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca e9 51 db 03 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000f8279f8 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000292030
RDX: 0000000000080000 RSI: ffffffff89813d08 RDI: ffff888029102540
RBP: ffffc9000f827d88 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: ffffc9000f827dcc R15: 0000000000000002
____sys_recvmsg+0x2f7/0x670 net/socket.c:2917
___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: 0033:0x7f5da339e019
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:00007f5da4304028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f5da3625fa0 RCX: 00007f5da339e019
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f5da343500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5da3626038 R14: 00007f5da3625fa0 R15: 00007ffd1acd2f98