rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13358/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=48741, q=191 ncpus=2)
task:syz.9.1458 state:R running task stack:25992 pid:13358 tgid:13356 ppid:12873 task_flags:0x40044c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108
irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
RIP: 0010:unwind_next_frame+0xc52/0x2390 arch/x86/kernel/unwind_orc.c:585
Code: 96 c0 20 c8 3c 01 0f 85 df 0c 00 00 48 89 df e8 84 23 00 00 48 89 c3 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 <4c> 8b 7c 24 18 74 08 4c 89 ff e8 2f 3a b1 00 49 89 1f 48 8b 44 24
RSP: 0018:ffffc9000ddf6f78 EFLAGS: 00000246
RAX: 1ffff92001bbee12 RBX: ffffffff81fc02f9 RCX: 1ffff92001bbee01
RDX: ffffffff903c80f0 RSI: 0000000000000002 RDI: ffffc9000ddf73b8
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff81729de5
R10: ffffc9000ddf7098 R11: ffffffff81acfa50 R12: ffffc9000ddf8000
R13: 1ffff92001bbee0b R14: ffffc9000ddf7048 R15: ffffc9000ddf0000
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:156
__reset_page_owner+0x71/0x1f0 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_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
folios_put_refs+0x559/0x640 mm/swap.c:992
free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x44c/0xb50 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x640/0x22e0 kernel/exit.c:943
do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd81af8e969
RSP: 002b:00007fd81bd0f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fd81b1b5fa8 RCX: 00007fd81af8e969
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fd81b1b5fac
RBP: 00007fd81b1b5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fd81b1b5fac
R13: 0000000000000000 R14: 00007fff42702050 R15: 00007fff42702138
rcu: rcu_preempt kthread timer wakeup didn't happen for 10503 jiffies! g48741 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=60725
rcu: rcu_preempt kthread starved for 10504 jiffies! g48741 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26824 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 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: 13343 Comm: syz.1.1456 Not tainted 6.15.0-next-20250530-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x10/0x18
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <75> 06 5a e9 58 3e 00 00 56 0f b6 f0 e8 9f ff ff ff 5e 5a e9 48 3e
RSP: 0018:ffffc90000a08c38 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff99d0ffe0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff99d0ffe0
RBP: 1ffffffff33a1ffd R08: ffffffff99d0ffe3 R09: 1ffffffff33a1ffc
R10: dffffc0000000000 R11: fffffbfff33a1ffd R12: dffffc0000000000
R13: 1ffffffff33a1ffe R14: ffffffff99d0fff0 R15: ffffffff99d0ffe8
FS: 00007feb238046c0(0000) GS:ffff888125d53000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ee10ff8 CR3: 000000001e2dc000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:562 [inline]
queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline]
do_raw_spin_unlock+0x122/0x240 kernel/locking/spinlock_debug.c:142
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock_irqrestore+0x78/0x110 kernel/locking/spinlock.c:194
debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
__run_hrtimer kernel/time/hrtimer.c:1729 [inline]
__hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 4b 7f 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 73 6a 28 f6 65 8b 05 5c 63 34 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc9000d926700 EFLAGS: 00000206
RAX: 02bdba16dcd3c200 RBX: 0000000000000a02 RCX: 02bdba16dcd3c200
RDX: 0000000000000002 RSI: ffffffff8d98278e RDI: 0000000000000001
RBP: ffffc9000d926790 R08: ffffffff8fa127f7 R09: 1ffffffff1f424fe
R10: dffffc0000000000 R11: fffffbfff1f424ff R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8880b8727ac0 R15: 1ffff92001b24ce0
qdisc_watchdog_schedule_ns include/net/pkt_sched.h:81 [inline]
cake_dequeue+0x46ba/0x4ab0 net/sched/sch_cake.c:-1
dequeue_skb net/sched/sch_generic.c:294 [inline]
qdisc_restart net/sched/sch_generic.c:399 [inline]
__qdisc_run+0x239/0x15f0 net/sched/sch_generic.c:417
__dev_xmit_skb net/core/dev.c:4171 [inline]
__dev_queue_xmit+0xfe1/0x3a70 net/core/dev.c:4679
dev_queue_xmit include/linux/netdevice.h:3355 [inline]
neigh_hh_output include/net/neighbour.h:523 [inline]
neigh_output include/net/neighbour.h:537 [inline]
ip_finish_output2+0xd03/0x1160 net/ipv4/ip_output.c:235
ip_local_out net/ipv4/ip_output.c:129 [inline]
__ip_queue_xmit+0x1101/0x1b00 net/ipv4/ip_output.c:527
__tcp_transmit_skb+0x225c/0x36c0 net/ipv4/tcp_output.c:1479
tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline]
tcp_send_syn_data net/ipv4/tcp_output.c:4064 [inline]
tcp_connect+0x2ac1/0x46f0 net/ipv4/tcp_output.c:4153
tcp_v4_connect+0x10e7/0x19d0 net/ipv4/tcp_ipv4.c:343
__inet_stream_connect+0x295/0xf10 net/ipv4/af_inet.c:677
tcp_sendmsg_fastopen+0x3a7/0x5e0 net/ipv4/tcp.c:1047
tcp_sendmsg_locked+0x4dd9/0x56f0 net/ipv4/tcp.c:1125
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1396
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:727
____sys_sendmsg+0x505/0x830 net/socket.c:2566
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb2298e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feb23804038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feb22bb5fa0 RCX: 00007feb2298e969
RDX: 0000000030004081 RSI: 0000200000000080 RDI: 0000000000000009
RBP: 00007feb22a10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feb22bb5fa0 R15: 00007ffddc8a5ea8