rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10515/1:b..l P14293/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=65589, q=1389776 ncpus=2)
task:syz.3.1678 state:R running task stack:23512 pid:14293 tgid:14293 ppid:10519 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1023/0x6000 kernel/sched/core.c:6907
preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:7184
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:753
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x21e/0x2e0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x3c3/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__set_page_owner+0x8c/0x540 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884
prep_new_page mm/page_alloc.c:1892 [inline]
get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3950
__alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5245
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x36/0x340 mm/mempolicy.c:2505
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1919
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1961
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2585
shmem_get_folio mm/shmem.c:2691 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3344
generic_perform_write+0x292/0xa40 mm/filemap.c:4314
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3519
__kernel_write_iter+0x2ac/0x920 fs/read_write.c:621
dump_emit_page fs/coredump.c:1299 [inline]
dump_user_range+0x3f9/0xb50 fs/coredump.c:1373
elf_core_dump+0x2d16/0x3c60 fs/binfmt_elf.c:2111
coredump_write fs/coredump.c:1050 [inline]
do_coredump fs/coredump.c:1127 [inline]
vfs_coredump+0x27b4/0x5570 fs/coredump.c:1201
get_signal+0x1f2a/0x21e0 kernel/signal.c:3019
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x1f8/0x670 kernel/entry/common.c:219
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fb420d9bf81
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb421015fa0 RCX: 00007fb420d9bf79
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fb420e327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fb421016038 R14: 00007fb421015fa0 R15: 00007fff36236f68
task:syz-executor state:R running task stack:23928 pid:10515 tgid:10515 ppid:10507 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1023/0x6000 kernel/sched/core.c:6907
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7234
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x19e/0x2e0 kernel/locking/lockdep.c:5893
Code: ff 65 0f c1 05 db 36 24 12 83 f8 01 0f 85 f7 00 00 00 9c 58 f6 c4 02 0f 85 0c 01 00 00 41 f7 c6 00 02 00 00 0f 85 99 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d ef 23 12 0f 85 0f 01 00 00 48 83 c4
RSP: 0018:ffffc9000b61f270 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e7e7220 RCX: ffffc9000b61f27c
RDX: 0000000000000002 RSI: ffffffff8de366b7 RDI: ffffffff8c1a9520
RBP: ffffffff81b6f49e R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000039e3b R12: ffff888027190000
R13: ffffc9000b61f328 R14: 0000000000000202 R15: 0000000000000003
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock include/linux/rcupdate.h:881 [inline]
class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x3c3/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:406
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5177 [inline]
__kmalloc_noprof+0x301/0x850 mm/slub.c:5189
kmalloc_noprof include/linux/slab.h:966 [inline]
tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x2af/0x3c0 security/tomoyo/file.c:776
tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
security_file_open+0xb5/0x1e0 security/security.c:2636
do_dentry_open+0x5aa/0x1660 fs/open.c:926
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9a7699b29c
RSP: 002b:00007ffecd6882b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9a76a31c3b RCX: 00007f9a7699b29c
RDX: 0000000000090800 RSI: 00007ffecd689460 RDI: 00000000ffffff9c
RBP: 00007ffecd68944c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffecd689460
R13: 00007f9a76a31c3b R14: 00000000000cc8cc R15: 00007ffecd6894a0
rcu: rcu_preempt kthread starved for 284 jiffies! g65589 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:28680 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1023/0x6000 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
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:467
ret_from_fork+0x754/0xd80 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 67 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:stack_depot_save_flags+0x35/0x9d0 lib/stackdepot.c:669
Code: 00 00 41 57 41 56 41 55 41 54 49 89 fc 55 89 d5 53 89 cb 48 83 ec 20 e8 09 0d d2 fc 41 89 c5 85 c0 74 09 80 3d 33 fa 22 16 00 <74> 15 48 83 c4 20 31 c0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc
RSP: 0018:ffffc90000a07c08 EFLAGS: 00000246
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000001
RDX: ffffffff8175e9aa RSI: 0000000000000024 RDI: ffffc90000a07d80
RBP: 0000000000000820 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 00000000000075e9 R12: ffffc90000a07c60
R13: 0000000000000024 R14: ffff88801df3c900 R15: 00000000000000f0
FS: 0000000000000000(0000) GS:ffff8881244a8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555607f14e8 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
kasan_save_stack+0x3f/0x50 mm/kasan/common.c:58
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4459 [inline]
slab_alloc_node mm/slub.c:4788 [inline]
kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4795
skb_clone+0x190/0x400 net/core/skbuff.c:2088
dev_queue_xmit_nit+0x255/0xa60 net/core/dev.c:2568
xmit_one net/core/dev.c:3862 [inline]
dev_hard_start_xmit+0x2fb/0x6c0 net/core/dev.c:3882
__dev_queue_xmit+0x6dd/0x46f0 net/core/dev.c:4832
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
neigh_hh_output include/net/neighbour.h:540 [inline]
neigh_output include/net/neighbour.h:554 [inline]
ip_finish_output2+0xf34/0x24b0 net/ipv4/ip_output.c:237
__ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:315
__ip_finish_output net/ipv4/ip_output.c:303 [inline]
ip_finish_output net/ipv4/ip_output.c:325 [inline]
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x39b/0xec0 net/ipv4/ip_output.c:438
dst_output include/net/dst.h:464 [inline]
ip_local_out+0x35b/0x4a0 net/ipv4/ip_output.c:131
synproxy_send_tcp.isra.0+0x481/0x680 net/netfilter/nf_synproxy_core.c:439
synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa73/0xd50 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e8/0x1930 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xee/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262
dst_input include/net/dst.h:474 [inline]
ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ip_rcv+0x2d9/0x5d0 net/ipv4/ip_input.c:573
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6152
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6265
process_backlog+0x37a/0x1580 net/core/dev.c:6617
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7681
napi_poll net/core/dev.c:7744 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7896
handle_softirqs+0x1ea/0x910 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x381/0x410 net/core/skbuff.c:674
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
nsim_dev_trap_report_work+0x2af/0xd10 drivers/net/netdevsim/dev.c:921
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245