rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=e5dc/1/0x4000000000000000 softirq=149055/149056 fqs=44
rcu: (detected by 1, t=10506 jiffies, g=141121, q=406 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31764 Comm: syz.3.3758 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:write_comp_data+0x7/0x90 kernel/kcov.c:240
Code: e0 16 00 00 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 d9 26 01 12 <49> 89 f8 49 89 f1 49 89 d2 65 48 8b 3d b0 26 01 12 a9 00 01 ff 00
RSP: 0018:ffffc90000007e80 EFLAGS: 00000046
RAX: 0000000080010002 RBX: 0000000000000000 RCX: ffffffff81f48331
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff8880b8428600 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888022ec4300
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b8428650
FS: 00007f87ce1946c0(0000) GS:ffff888124383000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000065a1d000 CR4: 00000000003526f0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:1945 [inline]
__hrtimer_run_queues+0x721/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count_sub+0x35/0x160 kernel/sched/core.c:5883
Code: 53 89 fb 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 d9 00 00 00 <8b> 0d 05 97 44 19 85 c9 75 1b 65 8b 05 aa 23 35 12 89 c2 81 e2 ff
RSP: 0018:ffffc90004177c80 EFLAGS: 00000297
RAX: 0000000000000003 RBX: 0000000000000001 RCX: 1ffffffff3632870
RDX: 0000000000000004 RSI: ffffffff81c6b909 RDI: 0000000000000001
RBP: ffff8880b85284c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff21ae22a
R13: 1ffff9200082ef9f R14: 0000000000000000 R15: 0000000000000000
percpu_up_read include/linux/percpu-rwsem.h:134 [inline]
cpus_read_unlock+0x73/0x150 kernel/cpu.c:502
class_cpus_read_lock_destructor include/linux/cpuhplock.h:48 [inline]
clock_was_set+0x657/0x870 kernel/time/hrtimer.c:988
do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108
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: 0033:0x7f87cd39ce59
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:00007f87ce194028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f87cd615fa0 RCX: 00007f87cd39ce59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f87cd432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f87cd616038 R14: 00007f87cd615fa0 R15: 00007ffcf879f798
rcu: rcu_preempt kthread starved for 10285 jiffies! g141121 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:27992 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
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: 18235 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x587/0x1700 kernel/smp.c:892
Code: 54 48 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 39 84 0c 00 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45
RSP: 0000:ffffc9000dc67888 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fc2c4d
RDX: ffff88803a98ca80 RSI: ffffffff81fc2c27 RDI: ffff88803a98ca80
RBP: ffff8880b8443360 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed101708866d R14: 0000000000000001 R15: ffff8880b853c600
FS: 00007faf78848880(0000) GS:ffff888124483000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ae0a26cfe8 CR3: 0000000025fbc000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 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+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:6443 [inline]
__handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6565
handle_mm_fault+0x37b/0xa30 mm/memory.c:6734
do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7faf780b5db7
Code: 00 00 00 41 55 48 89 d0 49 89 fd 41 54 49 89 f4 53 4c 89 c3 48 83 ec 10 48 39 4f 60 0f 84 c1 00 00 00 42 f6 44 01 08 01 74 59 <48> 83 61 08 fe 48 3d ff 03 00 00 76 69 49 8b 55 70 49 8d 75 60 48
RSP: 002b:00007ffd3217ec10 EFLAGS: 00010202
RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 000055ae0a26cfe0
RDX: 0000000000006010 RSI: 000055ae0a266fd0 RDI: 00007faf781f1ac0
RBP: 00007faf781f1ac0 R08: 00000000000001f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055ae0a266fd0
R13: 00007faf781f1ac0 R14: 00000000000001f0 R15: 00007faf781f1ac0