rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=8c1c/1/0x4000000000000000 softirq=29359/29372 fqs=0
rcu: (detected by 1, t=10506 jiffies, g=16021, q=713 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6831 Comm: syz.1.17 Not tainted 6.15.0-rc7-syzkaller-ga5806cd506af #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:hlock_class+0x13/0x70 kernel/locking/lockdep.c:233
Code: 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f b7 47 20 66 25 ff 1f 0f b7 c0 48 0f a3 05 5d 56 13 14 <73> 15 48 8d 04 80 48 8d 04 80 48 8d 04 c5 60 0f ab 95 e9 c6 63 d8
RSP: 0018:ffffc90000007c30 EFLAGS: 00000003
RAX: 0000000000000952 RBX: ffff888075475398 RCX: 00000000fd9dca83
RDX: 77554e1b38f2fd08 RSI: 000000000822f9e8 RDI: ffff888075475398
RBP: ffff888075475370 R08: 77554e1b38f2fd08 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000952
R13: 0000000000000001 R14: ffff888075474880 R15: 0000000000000000
FS: 00007f03c4f396c0(0000) GS:ffff8881249da000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f03c4f18d58 CR3: 00000000777c0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
validate_chain kernel/locking/lockdep.c:3877 [inline]
__lock_acquire+0xaa4/0x1ba0 kernel/locking/lockdep.c:5235
lock_acquire kernel/locking/lockdep.c:5866 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:924
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_unregister_key+0xdd/0x130 kernel/locking/lockdep.c:6613
Code: 48 89 ef e8 b5 fe ff ff 48 89 ef e8 cd e5 ff ff 89 c3 e8 f6 ee ff ff 9c 58 f6 c4 02 75 52 41 f7 c4 00 02 00 00 74 01 fb 84 db <75> 1b 5b 5d 41 5c e9 58 5d 0a 00 8b 05 16 97 ed 0e 31 db 85 c0 74
RSP: 0018:ffffc90003c77300 EFLAGS: 00000246
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dcd55d7 RDI: ffffffff8bf4a2a0
RBP: ffffffff97291018 R08: 00000000000151d6 R09: ffffffff95c6b36c
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000246
R13: ffff888033540000 R14: ffff88801bbc2000 R15: ffff888033540000
__qdisc_destroy+0x11a/0x4a0 net/sched/sch_generic.c:1080
qdisc_put+0xab/0xe0 net/sched/sch_generic.c:1106
taprio_attach+0x1fc/0x370 net/sched/sch_taprio.c:2147
qdisc_graft+0xe3f/0x17c0 net/sched/sch_api.c:1175
__tc_modify_qdisc net/sched/sch_api.c:1765 [inline]
tc_modify_qdisc+0xf14/0x2100 net/sched/sch_api.c:1821
rtnetlink_rcv_msg+0x3c6/0xe90 net/core/rtnetlink.c:6964
netlink_rcv_skb+0x16a/0x440 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x53d/0x7f0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
__sys_sendmsg+0x16d/0x220 net/socket.c:2652
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f03c418e969
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:00007f03c4f39038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f03c43b5fa0 RCX: 00007f03c418e969
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004
RBP: 00007f03c4210ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f03c43b5fa0 R15: 00007ffd562940f8
rcu: rcu_preempt kthread starved for 10506 jiffies! g16021 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:27704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 6832 Comm: modprobe Not tainted 6.15.0-rc7-syzkaller-ga5806cd506af #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x4a5/0x1290 kernel/smp.c:885
Code: 89 ee e8 de 12 0c 00 85 ed 74 48 48 8b 44 24 20 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 7d 17 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 de 0b 00 00 8b 43 08 31
RSP: 0018:ffffc90003cc79f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8441720 RCX: ffffffff81af2e99
RDX: ffff888079752440 RSI: ffffffff81af2e73 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170882e5
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b853b040
FS: 0000000000000000(0000) GS:ffff888124ada000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7e131ae9c CR3: 000000000e180000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1291 [inline]
flush_tlb_mm_range+0x322/0x1780 arch/x86/mm/tlb.c:1381
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:470 [inline]
tlb_flush_mmu mm/mmu_gather.c:403 [inline]
tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:496
exit_mmap+0x403/0xb90 mm/mmap.c:1297
__mmput+0x12a/0x410 kernel/fork.c:1380
mmput+0x62/0x70 kernel/fork.c:1402
exit_mm kernel/exit.c:589 [inline]
do_exit+0x9d1/0x2c30 kernel/exit.c:940
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1111
x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7e14796c5
Code: Unable to access opcode bytes at 0x7ff7e147969b.
RSP: 002b:00007fff0213b828 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ff7e157afe8 RCX: 00007ff7e14796c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007fff0213b7b8 R09: 0000000000000000
R10: 00007fff0213b650 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ff7e1579680 R15: 00007ff7e157b000