rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (5 ticks this GP) idle=823/1/0x4000000000000000 softirq=58093/58093 fqs=1
(detected by 1, t=10502 jiffies, g=96613, q=520)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 26162 Comm: syz.9.5839 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline]
RIP: 0010:kasan_check_range+0x10/0x290 mm/kasan/generic.c:189
Code: b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 41 57 41 56 <41> 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1 e8 2f
RSP: 0018:ffffc90000007c68 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff8880613182e8 RCX: ffffffff815e32a9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880613182e8
RBP: ffff888061318340 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd
R10: dffffc0000000000 R11: fffffbfff1b161be R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880613182ec R15: ffff888061318000
FS: 00007f93808be6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93808bed58 CR3: 0000000024ca9000 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]
atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
queued_spin_is_locked include/asm-generic/qspinlock.h:28 [inline]
debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline]
do_raw_spin_unlock+0x49/0x230 kernel/locking/spinlock_debug.c:140
__raw_spin_unlock include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:404 [inline]
advance_sched+0x66f/0x920 net/sched/sch_taprio.c:745
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 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:native_save_fl arch/x86/include/asm/irqflags.h:36 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:___might_sleep+0x181/0x610 kernel/sched/core.c:9626
Code: 7c 24 2c 75 70 42 c6 44 23 0c 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0 00 00 00 f7 84 24 a0 00 00 00 00 02 00 00 <42> c6 44 23 0c f8 74 43 4c 8d 7a 2c 4c 89 f8 48 c1 e8 03 42 0f b6
RSP: 0018:ffffc90004f07b40 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 1ffff920009e0f70 RCX: 97c3256eb1167b00
RDX: ffff8880206f0000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4200
RBP: ffffc90004f07c60 R08: ffffc90004f07707 R09: 1ffff920009e0ee0
R10: dffffc0000000000 R11: fffff520009e0ee1 R12: dffffc0000000000
R13: ffff8880206f043c R14: 1ffff110040de087 R15: 0000000000000000
__might_fault+0x6b/0x110 mm/memory.c:5354
do_recvmmsg+0x389/0x7f0 net/socket.c:2807
__sys_recvmmsg net/socket.c:2880 [inline]
__do_sys_recvmmsg net/socket.c:2903 [inline]
__se_sys_recvmmsg net/socket.c:2896 [inline]
__x64_sys_recvmmsg+0x195/0x250 net/socket.c:2896
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: 0033:0x7f9382686e99
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:00007f93808be028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f938290f090 RCX: 00007f9382686e99
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f938271ceaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f938290f128 R14: 00007f938290f090 R15: 00007ffdfb2e2e68
rcu: rcu_preempt kthread starved for 10499 jiffies! g96613 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:27520 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 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/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/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: 26164 Comm: syz.9.5839 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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+0x845/0x1120 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 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+0xba3/0xd80 kernel/smp.c:969
Code: 0f b6 44 05 00 84 c0 0f 85 9a 00 00 00 41 8b 1e 89 de 83 e6 01 31 ff e8 fb 73 0b 00 83 e3 01 75 07 e8 91 70 0b 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7
RSP: 0018:ffffc900052c7ae0 EFLAGS: 00000246
RAX: ffffffff816d9115 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc900150fd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900052c7c10 R08: ffff8880b913b3d7 R09: 1ffff1101722767a
R10: dffffc0000000000 R11: ffffed101722767b R12: ffff8880b913b3c0
R13: 1ffff11017208509 R14: ffff8880b9042848 R15: 0000000000000000
clock_was_set+0x7ac/0x880 kernel/time/hrtimer.c:959
do_settimeofday64+0x597/0x740 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: 0033:0x7f9382686e99
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:00007f938089d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f938290f180 RCX: 00007f9382686e99
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f938271ceaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f938290f218 R14: 00007f938290f180 R15: 00007ffdfb2e2e68