rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=174c/1/0x4000000000000000 softirq=88029/88029 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P20799/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=83697, q=340 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20814 Comm: syz.6.3703 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xa/0x20 kernel/kcov.c:314
Code: 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 00 00
RSP: 0018:ffffc90000a18d78 EFLAGS: 00000046
RAX: 181554ee58000000 RBX: 0000000000000002 RCX: ffffffff8931bc44
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff888079f78800 R08: 0000000000000006 R09: 181554ee54000000
R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
R13: ffff888079f78800 R14: ffff8880695cc340 R15: ffff888079f78400
FS:  00007f9eb3a056c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 000000005d89c000 CR4: 00000000003526f0
DR0: 0000000000040403 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 advance_sched+0x324/0xc60 net/sched/sch_taprio.c:960
 __run_hrtimer kernel/time/hrtimer.c:1739 [inline]
 __hrtimer_run_queues+0x20a/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:unwind_get_return_address+0x54/0xa0 arch/x86/kernel/unwind_orc.c:369
Code: 75 09 5b 31 c0 5d c3 cc cc cc cc 48 8d 6b 48 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 75 36 48 8b 7b 48 <e8> 47 36 1b 00 85 c0 74 cf 48 b8 00 00 00 00 00 fc ff df 48 89 ea
RSP: 0018:ffffc9000c507540 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc9000c507558 RCX: 0000000000000000
RDX: 1ffff920018a0eb4 RSI: ffffc9000c507d88 RDI: ffffffff820e9526
RBP: ffffc9000c5075a0 R08: ffffc9000c50758c R09: ffffffff910103a8
R10: ffffc9000c507558 R11: 0000000000010407 R12: ffffffff817a8580
R13: ffffc9000c507618 R14: 0000000000000000 R15: ffff88802afa2440
 arch_stack_walk+0xa7/0x100 arch/x86/kernel/stacktrace.c:26
 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
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4727
 ovl_cache_free fs/overlayfs/readdir.c:227 [inline]
 ovl_indexdir_cleanup+0x2aa/0x870 fs/overlayfs/readdir.c:1243
 ovl_get_indexdir fs/overlayfs/super.c:872 [inline]
 ovl_fill_super+0x4941/0x6720 fs/overlayfs/super.c:1404
 vfs_get_super fs/super.c:1280 [inline]
 get_tree_nodev+0xda/0x190 fs/super.c:1299
 vfs_get_tree+0x8f/0x380 fs/super.c:1814
 do_new_mount fs/namespace.c:3507 [inline]
 path_mount+0x14e6/0x1f20 fs/namespace.c:3834
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount fs/namespace.c:4034 [inline]
 __x64_sys_mount+0x294/0x320 fs/namespace.c:4034
 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: 0033:0x7f9eb2b7e819
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:00007f9eb3a05038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9eb2d35fa0 RCX: 00007f9eb2b7e819
RDX: 0000000020000340 RSI: 00000000200000c0 RDI: 0000000000000000
RBP: 00007f9eb2bf175e R08: 0000000020000080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9eb2d35fa0 R15: 00007ffc6a48d638
 </TASK>
task:syz.9.3698      state:R  running task     stack:27816 pid:20799 tgid:20798 ppid:16810  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6935
 preempt_schedule_thunk+0x1a/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:1705 [inline]
 zap_pmd_range mm/memory.c:1753 [inline]
 zap_pud_range mm/memory.c:1782 [inline]
 zap_p4d_range mm/memory.c:1803 [inline]
 unmap_page_range+0x1ec2/0x3d60 mm/memory.c:1824
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1870
 unmap_vmas+0x22f/0x490 mm/memory.c:1914
 exit_mmap+0x1c6/0xb30 mm/mmap.c:1667
 __mmput+0x12a/0x480 kernel/fork.c:1347
 mmput+0x62/0x70 kernel/fork.c:1369
 exit_mm kernel/exit.c:570 [inline]
 do_exit+0x9bf/0x2d70 kernel/exit.c:925
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3016
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2809f7e819
RSP: 002b:00007f280ad520e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f280a135fa8 RCX: 00007f2809f7e819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f280a135fa8
RBP: 00007f280a135fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f280a135fac
R13: 0000000000000000 R14: 00007fffc61d0ca0 R15: 00007fffc61d0d88
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g83697 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:27616 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: 9636 Comm: kworker/u8:17 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #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_pc+0x66/0x70 kernel/kcov.c:235
Code: 82 f8 15 00 00 83 f8 02 75 20 48 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 <c3> cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d217990 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8744a40 RCX: ffffffff8182a93c
RDX: ffff888037034880 RSI: ffffffff8182a916 RDI: 0000000000000005
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: 00007fed64d35f40 CR3: 000000000df7e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline]
 cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
 csd_lock_wait kernel/smp.c:340 [inline]
 smp_call_function_many_cond+0x456/0x1300 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>