rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5217/1:b..l P5846/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=73541, q=500343 ncpus=2)
task:syz-executor state:R running task stack:23144 pid:5846 tgid:5846 ppid:1 task_flags:0x40054c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
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+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1756 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0xf77/0x42c0 mm/memory.c:1889
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1932
unmap_vmas+0x218/0x470 mm/memory.c:1976
exit_mmap+0x1b9/0xb90 mm/mmap.c:1280
__mmput+0x12a/0x410 kernel/fork.c:1130
mmput+0x62/0x70 kernel/fork.c:1152
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f31b0f84e57
RSP: 002b:00007ffde5926d30 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000000000000062d RCX: 00007f31b0f84e57
RDX: 0000000040000000 RSI: 00007ffde5926d9c RDI: 00000000ffffffff
RBP: 00007ffde5926d9c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000001b4
R13: 0000555589941590 R14: 00000000000ab933 R15: 00007ffde5926df0
task:udevd state:R running task stack:24712 pid:5217 tgid:5217 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:217
Code: 8b 05 29 b4 1a 12 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c 16 00 00 85 c0 74 2b <8b> 82 18 16 00 00 83 f8 02 75 20 48 8b 8a 20 16 00 00 8b 92 1c 16
RSP: 0018:ffffc9000427f6f8 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 000000000004398f RCX: ffffffff822d8ca1
RDX: ffff8880611d4880 RSI: ffffffff822d8ce3 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008
R13: ffff88823ffef400 R14: 0000000000000000 R15: dffffc0000000000
__nr_to_section include/linux/mmzone.h:1941 [inline]
__pfn_to_section include/linux/mmzone.h:2079 [inline]
lookup_page_ext+0xa3/0x1d0 mm/page_ext.c:251
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__page_table_check_zero+0x1a4/0x5d0 mm/page_table_check.c:139
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1396 [inline]
__free_frozen_pages+0x7b7/0x10f0 mm/page_alloc.c:2895
discard_slab mm/slub.c:2753 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3218
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_kmalloc+0x8a/0xb0 mm/kasan/common.c:396
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4365 [inline]
__kmalloc_noprof+0x223/0x510 mm/slub.c:4377
kmalloc_noprof include/linux/slab.h:909 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45
tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822
security_inode_getattr+0x116/0x290 security/security.c:2377
vfs_getattr fs/stat.c:259 [inline]
vfs_statx_path fs/stat.c:299 [inline]
vfs_statx+0x121/0x3f0 fs/stat.c:356
vfs_fstatat+0x7b/0xf0 fs/stat.c:375
__do_sys_newfstatat+0x97/0x120 fs/stat.c:542
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: 0033:0x7f5103311b0a
RSP: 002b:00007ffd8e98d9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00005614e33b1418 RCX: 00007f5103311b0a
RDX: 00007ffd8e98d9c0 RSI: 00005614e339fef3 RDI: 00000000ffffff9c
RBP: 0000561517fbc668 R08: 00063d041628da3f R09: 00007f5103b73000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffd8e98d9c0 R14: 0000000000000000 R15: 00063d041628da3f
rcu: rcu_preempt kthread starved for 6944 jiffies! g73541 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:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
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:463
ret_from_fork+0x5d7/0x6f0 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 syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x60/0xc0 kernel/rcu/tree.c:751
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed 60 ee f5 8d 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02
RSP: 0018:ffffc90000a082e8 EFLAGS: 00000806
RAX: dffffc0000000000 RBX: ffff8880b85332a8 RCX: ffffffff819810fc
RDX: 0000000000000000 RSI: ffffffff8c162880 RDI: ffffffff8df5ee68
RBP: 0000000000000001 R08: 0000000000000001 R09: fffff5200014105a
R10: 0000000000000003 R11: 0000000000000000 R12: ffffffff84eb0a0f
R13: 0000000000000056 R14: 0000000000000056 R15: ffff8881c79349c0
FS: 0000000000000000(0000) GS:ffff8881247bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561517fb6be0 CR3: 000000000e380000 CR4: 00000000003526f0
Call Trace:
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5879
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194
__debug_check_no_obj_freed lib/debugobjects.c:1108 [inline]
debug_check_no_obj_freed+0x31f/0x600 lib/debugobjects.c:1129
slab_free_hook mm/slub.c:2348 [inline]
slab_free mm/slub.c:4680 [inline]
kmem_cache_free+0x2ac/0x4d0 mm/slub.c:4782
skb_kfree_head net/core/skbuff.c:1045 [inline]
skb_kfree_head net/core/skbuff.c:1042 [inline]
skb_free_head+0x1b7/0x210 net/core/skbuff.c:1059
skb_release_data+0x795/0x9e0 net/core/skbuff.c:1086
skb_release_all net/core/skbuff.c:1151 [inline]
__kfree_skb net/core/skbuff.c:1165 [inline]
consume_skb net/core/skbuff.c:1397 [inline]
consume_skb+0xbf/0x100 net/core/skbuff.c:1391
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
nft_synproxy_do_eval+0xa6b/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:5991
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6104
process_backlog+0x442/0x15e0 net/core/dev.c:6456
__napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7506
napi_poll net/core/dev.c:7569 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7696
handle_softirqs+0x216/0x8e0 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: 4c 62 02 c3 cc cc cc cc 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 d3 52 16 00 fb f4 4c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2
RAX: 0000000001f0663d RBX: 0000000000000001 RCX: ffffffff8b93bc29
RDX: 0000000000000000 RSI: ffffffff8de4fd50 RDI: ffffffff8c162900
RBP: ffffed1003c5d488 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2ea440 R14: ffffffff90ab4390 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