rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7342/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=19681, q=1349927 ncpus=2)
task:syz-executor state:R running task stack:23432 pid:7342 tgid:7342 ppid:1 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x118d/0x5df0 kernel/sched/core.c:6954
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7281
irqentry_exit+0x36/0x90 kernel/entry/common.c:196
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:220 [inline]
RIP: 0010:unwind_next_frame+0x297/0x20a0 arch/x86/kernel/unwind_orc.c:494
Code: 29 48 89 54 24 30 89 4c 24 28 89 74 24 20 44 89 5c 24 18 e8 bb c7 b6 00 48 8b 54 24 30 8b 4c 24 28 8b 74 24 20 44 8b 5c 24 18 <89> cf 8b 14 95 54 7e f9 91 48 8d 04 7f 48 8d 84 00 60 9f 36 91 83
RSP: 0018:ffffc9001c2d7830 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 0000000000000001 RCX: 000000000000ddd7
RDX: 00000000000061fb RSI: 00000000000a8f3c RDI: ffffffff91fb0640
RBP: ffffc9001c2d7938 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000061fa R12: ffffc9001c2d7940
R13: ffffc9001c2d78f0 R14: ffffc9001c2d7925 R15: ffffffff8161fa72
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
__free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706
discard_slab mm/slub.c:2752 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3217
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4179 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4247
__d_alloc+0x32/0xae0 fs/dcache.c:1690
d_alloc_pseudo+0x1c/0xc0 fs/dcache.c:1821
alloc_path_pseudo fs/file_table.c:363 [inline]
alloc_file_pseudo+0xcf/0x230 fs/file_table.c:379
sock_alloc_file+0x50/0x210 net/socket.c:470
sock_map_fd net/socket.c:500 [inline]
__sys_socket+0x1c0/0x260 net/socket.c:1740
__do_sys_socket net/socket.c:1745 [inline]
__se_sys_socket net/socket.c:1743 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1743
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe27b908c7
RSP: 002b:00007ffe6cef8d78 EFLAGS: 00000202 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007efe27b908c7
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a
RBP: 00007ffe6cef94ac R08: 0000000000000000 R09: 00007ffe6cef91b7
R10: 0000000000000000 R11: 0000000000000202 R12: 00007efe27d81c80
R13: 00005555685b2590 R14: 0000000000039b8a R15: 00007efe27d83e40
rcu: rcu_preempt kthread starved for 10367 jiffies! g19681 f0x2 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x118d/0x5df0 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7051
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 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:
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-06699-ge8d780dcd957 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:stack_trace_consume_entry+0x1e/0x170 kernel/stacktrace.c:83
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 48 89 fb 48 83 c7 10 48 89 fa 48 c1 ea 03 <48> 83 ec 08 0f b6 04 02 84 c0 74 08 3c 03 0f 8e e7 00 00 00 48 8d
RSP: 0018:ffffc90000a08040 EFLAGS: 00000a02
RAX: dffffc0000000000 RBX: ffffc90000a08118 RCX: ffffc90000a07fac
RDX: 1ffff92000141025 RSI: ffffffff8b8b7103 RDI: ffffc90000a08128
RBP: ffffc90000a080e8 R08: ffffffff91f20956 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000a8b47 R12: ffffffff81a6e0b0
R13: ffffc90000a08118 R14: 0000000000000000 R15: ffff88801e6ba440
FS: 0000000000000000(0000) GS:ffff88812481e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a60296c150 CR3: 0000000036130000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4179 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4280
__alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
synproxy_send_client_synack+0x1af/0x8f0 net/netfilter/nf_synproxy_core.c:460
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e6/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:260
dst_input include/net/dst.h:471 [inline]
ip_rcv_finish net/ipv4/ip_input.c:454 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5979
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6092
process_backlog+0x442/0x15e0 net/core/dev.c:6444
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7497
napi_poll net/core/dev.c:7560 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7687
handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 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+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: cb 66 02 e9 43 0b 03 00 0f 1f 00 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 c3 bc 1e 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 00000000012b9491 RBX: 0000000000000001 RCX: ffffffff8b8b5c99
RDX: 0000000000000000 RSI: ffffffff8de12f1c RDI: ffffffff8c160b80
RBP: ffffed1003cd7488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801e6ba440 R14: ffffffff90a7d650 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148