rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=249c/1/0x4000000000000000 softirq=21762/21773 fqs=0
rcu: (detected by 0, t=10502 jiffies, g=17321, q=425 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6340 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:lock_is_held_type+0x3f/0x150 kernel/locking/lockdep.c:5933
Code: e6 12 62 04 00 0f 84 e4 00 00 00 65 8b 05 c9 30 6d 07 85 c0 0f 85 d5 00 00 00 65 4c 8b 2d 11 eb 6c 07 41 83 bd 54 0b 00 00 00 <0f> 85 bf 00 00 00 89 f5 49 89 fe 9c 41 5c fa 48 c7 c7 01 65 f1 8d
RSP: 0018:ffffc90000a08c38 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000010000
RDX: ffff888028f99e80 RSI: 00000000ffffffff RDI: ffff88801ee9c2c0
RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200014117c R12: ffff88801ee9c300
R13: ffff888028f99e80 R14: dffffc0000000000 R15: ffff888033093400
FS: 0000555576743500(0000) GS:ffff888125551000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f04bb4744c0 CR3: 000000003237c000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0x160/0xc90 net/sched/sch_taprio.c:933
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x16d/0x23c0 arch/x86/kernel/unwind_orc.c:510
Code: d8 48 c1 e8 03 0f b6 04 28 84 c0 0f 85 4e 1b 00 00 f6 03 03 0f 85 e5 18 00 00 49 8d 5e 35 48 89 d8 48 c1 e8 03 48 89 44 24 28 <0f> b6 04 28 84 c0 0f 85 45 1b 00 00 4c 89 6c 24 48 4c 89 64 24 20
RSP: 0018:ffffc900039c76b8 EFLAGS: 00000a07
RAX: 1ffff92000738f03 RBX: ffffc900039c781d RCX: 0000000080000001
RDX: 0000000028b53707 RSI: ffffffff8c27d560 RDI: ffffffff8c27d520
RBP: dffffc0000000000 R08: ffffffff81768a55 R09: ffffffff8e75e5a0
R10: ffffc900039c7838 R11: fffff52000738f09 R12: 1ffff92000738efd
R13: ffffc900039c7838 R14: ffffc900039c77e8 R15: ffffffff81768a55
__unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x187/0x630 mm/slub.c:6295
sk_prot_free net/core/sock.c:2282 [inline]
__sk_destruct+0x614/0x880 net/core/sock.c:2384
sock_put include/net/sock.h:2007 [inline]
unix_release_sock+0xa3e/0xc80 net/unix/af_unix.c:732
unix_release+0x92/0xd0 net/unix/af_unix.c:1184
__sock_release net/socket.c:662 [inline]
sock_close+0xc3/0x240 net/socket.c:1455
__fput+0x44f/0xa70 fs/file_table.c:469
fput_close_sync+0x11f/0x240 fs/file_table.c:574
__do_sys_close fs/open.c:1509 [inline]
__se_sys_close fs/open.c:1494 [inline]
__x64_sys_close+0x7e/0x110 fs/open.c:1494
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd3e4f994a7
Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 da c0 fb ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff5cac1638 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fd3e4f994a7
RDX: 0000000000000000 RSI: 0000000000008933 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000000 R09: 00000000fffffff9
R10: 0000000000000002 R11: 0000000000000246 R12: 00007fff5cac16c0
R13: 00007fd3e502e3d6 R14: 00007fd3e5d04620 R15: 00007fd3e502e3d6
rcu: rcu_preempt kthread starved for 10502 jiffies! g17321 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:27776 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 0 UID: 0 PID: 6472 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcea/0x12c0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 d4 eb 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7f e7 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 63 e7 0b 00 eb e4 44
RSP: 0018:ffffc9000237f580 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170e813d RCX: ffff888028c23d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000237f6a8 R08: ffffffff9011e4b7 R09: 1ffffffff2023c96
R10: dffffc0000000000 R11: fffffbfff2023c97 R12: ffff8880b87409e8
R13: dffffc0000000000 R14: ffff8880b863c000 R15: 0000000000000001
FS: 00007fc959324c80(0000) GS:ffff888125451000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055be2cd47048 CR3: 0000000020bc6000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472
dup_mmap+0x17a2/0x1d90 mm/mmap.c:1906
dup_mm kernel/fork.c:1531 [inline]
copy_mm+0x13b/0x4a0 kernel/fork.c:1583
copy_process+0x18b6/0x3cd0 kernel/fork.c:2223
kernel_clone+0x248/0x8e0 kernel/fork.c:2653
__do_sys_clone kernel/fork.c:2794 [inline]
__se_sys_clone kernel/fork.c:2778 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc9594be636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007fff3fced6c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff3fced6c8 RCX: 00007fc9594be636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 000055be2cd45c30 R08: 0000000000000000 R09: 3c00000040001201
R10: 00007fc959324f50 R11: 0000000000000246 R12: 000055be2cd53820
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000