rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=173c/0/0x1 softirq=157865/157866 fqs=112
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22077/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=129733, q=275 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:314
Code: 48 89 44 11 20 c3 cc 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 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 14 25 08 90 9c 92 65 8b 0d 18 66 dc 10 81 e1 00 01 ff 00
RSP: 0018:ffffc90000a08d00 EFLAGS: 00000046
RAX: ffffffff81aea829 RBX: ffff8880294ce340 RCX: ffff88801d2bda00
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000020
RBP: 0000000000000010 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e
R10: dffffc0000000000 R11: fffffbfff1f4167f R12: dffffc0000000000
R13: 1ffff110170e4f78 R14: ffff8880b8727bc0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efc086e56c0 CR3: 0000000049ff0000 CR4: 00000000003526f0
Call Trace:
enqueue_hrtimer+0x139/0x3a0 kernel/time/hrtimer.c:1091
__run_hrtimer kernel/time/hrtimer.c:1778 [inline]
__hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: c684edac0851cb00 RBX: ffffffff81976918 RCX: c684edac0851cb00
RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa0b3f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a57b40
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:749
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147
task:syz.8.2936 state:R running task stack:25032 pid:22077 tgid:22076 ppid:18141 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:746
Code: 89 f7 e8 2c e2 78 00 48 c7 c3 58 bf 9d 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 39 65 f5 10 <74> 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f e9 17 38 c2 09 cc e8 a1 7b
RSP: 0018:ffffc9000caaf358 EFLAGS: 00000286
RAX: 000000000211172c RBX: ffff8880b8732f58 RCX: 72022c17d1a90600
RDX: 0000000000000000 RSI: ffffffff8be1ba20 RDI: ffffffff8be1b9e0
RBP: ffffffff8172aae5 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000caaf598 R11: fffff52001955eb5 R12: 0000000000000002
R13: ffffffff8e13f0e0 R14: ffffffff8dba8c78 R15: dffffc0000000000
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5834
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
kmem_cache_alloc_bulk_noprof+0x4e0/0x790 mm/slub.c:5374
__io_alloc_req_refill+0x9d/0x280 io_uring/io_uring.c:972
io_alloc_req io_uring/io_uring.h:447 [inline]
io_submit_sqes+0xc31/0x1c50 io_uring/io_uring.c:2326
__do_sys_io_uring_enter io_uring/io_uring.c:3404 [inline]
__se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3338
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f316718eb69
RSP: 002b:00007f3167fea038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f31673b5fa0 RCX: 00007f316718eb69
RDX: 0000000000000000 RSI: 00000000000847ba RDI: 0000000000000007
RBP: 00007f3167211df1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f31673b5fa0 R15: 00007ffca1f852c8
rcu: rcu_preempt kthread starved for 10277 jiffies! g129733 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:26120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5397 [inline]
__schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
__schedule_loop kernel/sched/core.c:6864 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6879
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2
RAX: 9aef0ad8e78b7700 RBX: ffffffff81976918 RCX: 9aef0ad8e78b7700
RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa0b3f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0b73974e9c CR3: 000000005f60c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:749
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:185 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:325
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
rest_init+0x2de/0x300 init/main.c:745
start_kernel+0x47d/0x500 init/main.c:1102
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147