syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=a184/1/0x4000000000000000 softirq=36371/36372 fqs=1
rcu: 	(detected by 1, t=10502 jiffies, g=22057, q=188 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8548 Comm: syz.1.565 Not tainted 6.16.0-rc3-syzkaller-00233-g35e261cd95dd #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:advance_sched+0x41d/0xc80 net/sched/sch_taprio.c:961
Code: dc 06 00 00 48 b9 00 00 00 00 00 fc ff df 4c 89 f8 48 c1 e8 03 80 3c 08 00 0f 85 d5 06 00 00 48 8b 44 24 10 49 8b 1f 80 38 00 <0f> 85 d1 06 00 00 48 8b 44 24 08 48 89 df 48 8b a8 30 01 00 00 48
RSP: 0018:ffffc90000007d90 EFLAGS: 00000046
RAX: ffffed100fb438a6 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88805b954880 RSI: ffffffff8993760a RDI: 0000000000000005
RBP: ffff88807da1c400 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: ffff88807da1cc00
FS:  00007ffbf1e226c0(0000) GS:ffff888124752000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001a3030 CR3: 000000006eb75000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __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:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 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+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 36 00 15 f6 48 89 df e8 1e 54 15 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 55 74 05 f6 65 8b 05 4e 6a 49 08 85 c0 74 16 5b
RSP: 0018:ffffc90003f37858 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff888029277a80 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8de1a526 RDI: ffffffff8c157ee0
RBP: 0000000000000282 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90a81657 R11: 0000000000000000 R12: 0000000000000002
R13: ffff8880292778f0 R14: ffff888029277ac0 R15: ffff888029277468
 __unix_dgram_recvmsg+0x313/0xc50 net/unix/af_unix.c:2541
 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2616
 sock_recvmsg_nosec net/socket.c:1017 [inline]
 ____sys_recvmsg+0x5f9/0x6b0 net/socket.c:2784
 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2828
 do_recvmmsg+0x2fe/0x750 net/socket.c:2923
 __sys_recvmmsg net/socket.c:2997 [inline]
 __do_sys_recvmmsg net/socket.c:3020 [inline]
 __se_sys_recvmmsg net/socket.c:3013 [inline]
 __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3013
 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: 0033:0x7ffbf0f8e929
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:00007ffbf1e22038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007ffbf11b6080 RCX: 00007ffbf0f8e929
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007ffbf1010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007ffbf11b6080 R15: 00007ffee9d44ec8
 </TASK>
rcu: rcu_preempt kthread starved for 10499 jiffies! g22057 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:27928 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 8550 Comm: syz.2.566 Not tainted 6.16.0-rc3-syzkaller-00233-g35e261cd95dd #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+0xd7b/0x1510 kernel/smp.c:885
Code: e8 2a 1a 0c 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 c7 1e 0c 00 f3 90 <41> 0f b6 06 41 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff
RSP: 0018:ffffc90004a4f598 EFLAGS: 00000246
RAX: 0000000000080000 RBX: ffff8880b84421e0 RCX: ffffc9000c9fa000
RDX: 0000000000080000 RSI: ffffffff81b001a9 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: 0000000000000003 R14: ffffed101708843d R15: ffff8880b853b580
FS:  00007f15b4d7f6c0(0000) GS:ffff888124852000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3d62e3 CR3: 000000001296e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
 smp_text_poke_batch_finish+0x27b/0xdb0 arch/x86/kernel/alternative.c:2901
 __static_call_transform+0x33b/0x740 arch/x86/kernel/static_call.c:111
 arch_static_call_transform+0xb6/0xc0 arch/x86/kernel/static_call.c:163
 __static_call_update+0xef/0x670 kernel/static_call_inline.c:147
 tracepoint_update_call kernel/tracepoint.c:271 [inline]
 tracepoint_add_func+0xa88/0xea0 kernel/tracepoint.c:312
 tracepoint_probe_register_prio_may_exist+0xb9/0x100 kernel/tracepoint.c:435
 tracepoint_probe_register_may_exist include/linux/tracepoint.h:50 [inline]
 bpf_probe_register+0x189/0x200 kernel/trace/bpf_trace.c:2326
 bpf_raw_tp_link_attach+0x2cc/0x600 kernel/bpf/syscall.c:4007
 bpf_raw_tracepoint_open kernel/bpf/syscall.c:4038 [inline]
 __sys_bpf+0x3b4/0x4d80 kernel/bpf/syscall.c:5878
 __do_sys_bpf kernel/bpf/syscall.c:5943 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5941 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5941
 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: 0033:0x7f15b3f8e929
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:00007f15b4d7f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f15b41b5fa0 RCX: 00007f15b3f8e929
RDX: 0000000000000010 RSI: 00002000000004c0 RDI: 0000000000000011
RBP: 00007f15b4010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f15b41b5fa0 R15: 00007ffeadf16f08
 </TASK>