syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=abf4/1/0x4000000000000000 softirq=150238/150238 fqs=11
rcu: 	(detected by 0, t=10502 jiffies, g=156421, q=158 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31307 Comm: syz.2.5742 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:find_held_lock+0x0/0x110 kernel/locking/lockdep.c:5332
Code: 46 ff 86 00 e9 11 ff ff ff e8 3c ff 86 00 4c 8d 44 24 20 eb 95 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 57 44 8d 7a ff 49 63 c7 41 56 49 89 ce 48 8d 04 80 41 55 49 89
RSP: 0018:ffffc90000a18c18 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 1ffff92000143186 RCX: ffffc90000a18c70
RDX: 0000000000000002 RSI: ffffffff9a9d3668 RDI: ffff888029604880
RBP: 0000000000000007 R08: 0000000000000000 R09: fffffbfff20be6aa
R10: ffffffff905f3557 R11: 0000000000000001 R12: ffffffff9a9d3668
R13: 0000000000000002 R14: ffff888029605358 R15: ffff888029604880
FS:  00007fb945a156c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002057f000 CR3: 000000006d3d0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000ccef DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __lock_release kernel/locking/lockdep.c:5524 [inline]
 lock_release+0x227/0x6f0 kernel/locking/lockdep.c:5870
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194
 debug_object_activate+0x2e6/0x4a0 lib/debugobjects.c:836
 debug_hrtimer_activate kernel/time/hrtimer.c:428 [inline]
 debug_activate kernel/time/hrtimer.c:469 [inline]
 enqueue_hrtimer+0x25/0x3c0 kernel/time/hrtimer.c:1076
 __run_hrtimer kernel/time/hrtimer.c:1756 [inline]
 __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1803
 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x10f/0x400 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find+0x70/0xf0 arch/x86/kernel/unwind_orc.c:102
Code: ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48 c1 ea 3f 48 c1 fe 02 48 01 f2 48 d1 fa 48 8d 5c 95 00 48 89 da 48 c1 ea 03 0f b6 34 0a <48> 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13
RSP: 0018:ffffc9000bf37198 EFLAGS: 00000a03
RAX: ffffffff918ca212 RBX: ffffffff90d7118c RCX: dffffc0000000000
RDX: 1ffffffff21ae231 RSI: 0000000000000000 RDI: ffffffff90d7118c
RBP: ffffffff90d7118c R08: ffffffff918ca218 R09: ffffffff9180670c
R10: ffffc9000bf37248 R11: 000000000008d24c R12: ffffffff90d7118c
R13: ffffffff89d24c47 R14: ffffffff90d7118c R15: ffffffff90d7118c
 orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
 unwind_next_frame+0x2be/0x20c0 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x95/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x223/0x3c0 mm/slub.c:4220
 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1323 [inline]
 alloc_skb_with_frags+0xe4/0x850 net/core/skbuff.c:6612
 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2881
 unix_dgram_sendmsg+0x4b8/0x19e0 net/unix/af_unix.c:2027
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg net/socket.c:726 [inline]
 ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2583
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637
 __sys_sendmmsg+0x201/0x420 net/socket.c:2726
 __do_sys_sendmmsg net/socket.c:2753 [inline]
 __se_sys_sendmmsg net/socket.c:2750 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2750
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb944b85d29
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:00007fb945a15038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb944d75fa0 RCX: 00007fb944b85d29
RDX: 0000000000000651 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007fb944c01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb944d75fa0 R15: 00007ffec437c3f8
 </TASK>
rcu: rcu_preempt kthread starved for 10480 jiffies! g156421 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:27744 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 26769 Comm: kworker/u8:45 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:314
Code: bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc90005747990 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880b8744a40 RCX: ffffffff818e071c
RDX: ffff88807559a440 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170e8949
R13: 0000000000000001 R14: ffff8880b8744a48 R15: ffff8880b863fe40
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020360030 CR3: 000000000df7e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000ccef DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 csd_lock_wait kernel/smp.c:340 [inline]
 smp_call_function_many_cond+0x47c/0x1300 kernel/smp.c:884
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1051
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2114 [inline]
 text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2324
 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:2512 [inline]
 text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:849 [inline]
 toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
vkms_vblank_simulate: vblank timer overrun