rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (64 ticks this GP) idle=e8d/1/0x4000000000000000 softirq=30214/30214 fqs=5
(detected by 1, t=10502 jiffies, g=45845, q=237)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11703 Comm: syz.0.2193 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:101 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x62/0x290 mm/kasan/generic.c:189
Code: 00 00 fc ff df 49 89 fe 49 c1 ee 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 16 4c 8d 44 3e ff 4d 89 c1 49 c1 e9 03 4b 8d 1c 21 <49> 89 df 4d 29 df 49 83 ff 10 7f 29 4d 85 ff 0f 84 38 01 00 00 4c
RSP: 0018:ffffc900000078d0 EFLAGS: 00000803
RAX: 0000000000000001 RBX: fffffbfff203ac1a RCX: ffffffff815d1c7a
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d60c8
RBP: ffffc90000007b50 R08: ffffffff901d60cf R09: 1ffffffff203ac19
R10: dffffc0000000000 R11: fffffbfff203ac19 R12: dffffc0000000001
R13: 0000000000000008 R14: 1ffffffff203ac19 R15: ffff8880561ae430
FS: 00007f710ed3b6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7110b50540 CR3: 0000000078426000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
hlock_class kernel/locking/lockdep.c:197 [inline]
check_wait_context kernel/locking/lockdep.c:4686 [inline]
__lock_acquire+0x52a/0x7d10 kernel/locking/lockdep.c:4962
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1689 [inline]
__hrtimer_run_queues+0x5a9/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
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:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:92
Code: 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a
RSP: 0018:ffffc90003327a60 EFLAGS: 00040202
RAX: ffffffff83e40801 RBX: 0000000000000038 RCX: 0000000000000007
RDX: 0000000000000000 RSI: 0000200000339000 RDI: ffffc90003327b00
RBP: 0000000000000000 R08: 0000000000000000 R09: 1ffff92000664f66
R10: dffffc0000000000 R11: fffff52000664f67 R12: 00007ffffffff000
R13: 0000200000339038 R14: ffffc90003327b00 R15: 0000200000339000
copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
_copy_from_user+0xfa/0x170 lib/usercopy.c:23
copy_from_user include/linux/uaccess.h:192 [inline]
__copy_msghdr_from_user net/socket.c:2327 [inline]
copy_msghdr_from_user net/socket.c:2378 [inline]
recvmsg_copy_msghdr net/socket.c:2630 [inline]
___sys_recvmsg+0x173/0x5c0 net/socket.c:2702
do_recvmmsg+0x382/0x850 net/socket.c:2800
__sys_recvmmsg net/socket.c:2879 [inline]
__do_sys_recvmmsg net/socket.c:2902 [inline]
__se_sys_recvmmsg net/socket.c:2895 [inline]
__x64_sys_recvmmsg+0x195/0x250 net/socket.c:2895
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: 0033:0x7f7110b02e59
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:00007f710ed3b028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f7110d7c090 RCX: 00007f7110b02e59
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f7110b98d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7110d7c128 R14: 00007f7110d7c090 R15: 00007fffde918ce8
rcu: rcu_preempt kthread starved for 10408 jiffies! g45845 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:28016 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 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 1
CPU: 1 PID: 11711 Comm: syz.1.2194 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 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+0x1110/0x1270 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+0x843/0x1120 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:2021
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:1685 [inline]
__hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
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:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xbb5/0xd90 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 d9 62 0b 00 83 e3 01 75 07 e8 6f 5f 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc9000315fae0 EFLAGS: 00000246
RAX: ffffffff816dd6c8 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000eded000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000315fc10 R08: ffff8880b913b3d7 R09: 1ffff1101722767a
R10: dffffc0000000000 R11: ffffed101722767b R12: ffff8880b9042848
R13: 1ffff11017208509 R14: ffff8880b913b3c0 R15: 0000000000000000
clock_was_set+0x781/0x850 kernel/time/hrtimer.c:959
do_settimeofday64+0x5b6/0x760 kernel/time/timekeeping.c:1328
__do_sys_clock_settime kernel/time/posix-timers.c:1125 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline]
__x64_sys_clock_settime+0x25a/0x2a0 kernel/time/posix-timers.c:1113
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: 0033:0x7f33c8635e59
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:00007f33c686e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f33c88af090 RCX: 00007f33c8635e59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f33c86cbd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f33c88af128 R14: 00007f33c88af090 R15: 00007ffd2e9337c8