rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12347/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=77581, q=1168 ncpus=2)
task:syz.0.1708 state:R running task stack:26648 pid:12347 tgid:12347 ppid:5823 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7050
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7074
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3c17/0x44e0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0x118/0x430 kernel/fork.c:1177
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x850/0x25b0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f24e458f749
RSP: 002b:00007ffcd66a83f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffff92 RBX: 0000000000083dc1 RCX: 00007f24e458f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f24e47e5fac
RBP: 0000000000000bea R08: 3fffffffffffffff R09: 00000002d66a86ef
R10: 00007ffcd66a84f0 R11: 0000000000000246 R12: 00007f24e47e5fac
R13: 00007ffcd66a84f0 R14: 00000000000849ab R15: 00007ffcd66a8510
rcu: rcu_preempt kthread starved for 321 jiffies! g77581 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
__schedule_loop kernel/sched/core.c:6948 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6963
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 101 PID: 5492 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:unwind_next_frame+0x188/0x23d0 arch/x86/kernel/unwind_orc.c:-1
Code: 8d 5e 35 48 89 d8 48 c1 e8 03 48 89 44 24 28 0f b6 04 28 84 c0 0f 85 4c 1b 00 00 4c 89 6c 24 48 4c 89 64 24 20 4c 89 7c 24 50 <48> 89 5c 24 18 0f b6 1b 48 8b 44 24 30 80 3c 28 00 4c 8b 7c 24 10
RSP: 0018:ffffc90000a07b58 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000a07c5d RCX: 875947bfc6b07500
RDX: 00000000a42637f2 RSI: ffffffff8be247c0 RDI: ffffffff8be24780
RBP: dffffc0000000000 R08: ffffffff81746f85 R09: ffffffff8e33f2e0
R10: ffffc90000a07c78 R11: ffffffff81addd50 R12: 1ffff92000140f85
R13: ffffc90000a07c78 R14: ffffc90000a07c28 R15: ffffffff81746f85
FS: 00007f2c4ca9e740(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa860000218 CR3: 0000000032b38000 CR4: 00000000003526f0
DR0: 0000000000000008 DR1: 0000000000000002 DR2: 0000000000000404
DR3: ffffffffefffff18 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5319
__alloc_skb+0x255/0x430 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack+0x16c/0xe20 net/netfilter/nf_synproxy_core.c:460
nft_synproxy_eval_v4+0x36e/0x560 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x345/0x570 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x40c/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x25d/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6138 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6251
process_backlog+0x622/0x1500 net/core/dev.c:6603
__napi_poll+0xae/0x320 net/core/dev.c:7667
napi_poll net/core/dev.c:7730 [inline]
net_rx_action+0x672/0xe50 net/core/dev.c:7882
handle_softirqs+0x27d/0x850 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 91 25 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900038274b8 EFLAGS: 00000206
RAX: 875947bfc6b07500 RBX: 0000000000000000 RCX: 875947bfc6b07500
RDX: 00000000593d26b5 RSI: ffffffff8dc93c7b RDI: ffffffff8be247e0
RBP: ffffffff81746f85 R08: ffffffff81746f85 R09: ffffffff8e33f2e0
R10: ffffc90003827678 R11: ffffffff81addd50 R12: 0000000000000002
R13: ffffffff8e33f2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x146/0x170 mm/slub.c:3886
put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961
__slab_free+0x288/0x2a0 mm/slub.c:5956
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
__do_kmalloc_node mm/slub.c:5660 [inline]
__kmalloc_noprof+0x3cf/0x800 mm/slub.c:5673
kmalloc_noprof include/linux/slab.h:961 [inline]
tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723
security_file_ioctl+0xcb/0x2d0 security/security.c:2435
__do_sys_ioctl fs/ioctl.c:591 [inline]
__se_sys_ioctl+0x47/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c4cb9e378
Code: 00 00 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 07 89 d0 c3 0f 1f 40 00 48 8b 15 49 3a 0d
RSP: 002b:00007ffda1b1a5c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000055ad2d8ea220 RCX: 00007f2c4cb9e378
RDX: 00007ffda1b1a5d0 RSI: 0000000000008921 RDI: 000000000000000f
RBP: 00007ffda1b1a5d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000055ad2d8ed540
R13: 000055ad2d8ea220 R14: 000055ad2d8ed540 R15: 00007ffda1b1a820