rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=5b1c/1/0x4000000000000000 softirq=34930/34934 fqs=2 rcu: (detected by 0, t=10506 jiffies, g=51105, q=202 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13751 Comm: syz.4.3783 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31 Code: db eb d0 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 <31> d2 e9 6f e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RSP: 0018:ffffc90000a189e0 EFLAGS: 00000047 RAX: 0000000000000000 RBX: 0000000000000021 RCX: ffffffff81703f9a RDX: 0000000000000008 RSI: 0000000000000008 RDI: ffffffff93fa6840 RBP: 0000000000000009 R08: ffffffff93fa6847 R09: 1ffffffff27f4d08 R10: dffffc0000000000 R11: fffffbfff27f4d09 R12: ffff888028601e00 R13: dffffc0000000000 R14: 0000000000000200 R15: ffff8880286028e0 FS: 000055558b248500(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c61eff8 CR3: 000000002a966000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:227 [inline] mark_lock+0x9a/0x350 kernel/locking/lockdep.c:4655 mark_usage kernel/locking/lockdep.c:4598 [inline] __lock_acquire+0xc35/0x2040 kernel/locking/lockdep.c:5096 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_switch+0xa4/0x120 kernel/kcov.c:350 Code: 8b 00 00 00 4c 8b 4c 24 20 65 4c 8b 1c 25 c0 d6 03 00 31 d2 eb 08 48 ff c2 49 39 d2 74 71 4c 8b 74 d6 10 65 8b 05 44 44 70 7e <25> 00 01 ff 00 74 11 3d 00 01 00 00 75 de 41 83 bb 1c 16 00 00 00 RSP: 0018:ffffc9000ab9f860 EFLAGS: 00000202 RAX: 0000000080000001 RBX: 0000000000000002 RCX: ffff888028601e00 RDX: 0000000000000001 RSI: ffffffff8e5a3d80 RDI: 0000000000000002 RBP: ffffffff90885fac R08: 0000000000000003 R09: ffffffff81412e12 R10: 0000000000000002 R11: ffff888028601e00 R12: ffffffff900fb1d8 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff90885fa8 unwind_next_frame+0x6c2/0x2a00 arch/x86/kernel/unwind_orc.c:505 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2256 [inline] slab_free mm/slub.c:4477 [inline] kmem_cache_free+0x145/0x350 mm/slub.c:4552 file_free+0x24/0x1f0 fs/file_table.c:65 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd37ed7def9 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:00007ffe9d11edc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000004b126 RCX: 00007fd37ed7def9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fd37ef37a80 R08: 0000000000000001 R09: 00007ffe9d11f0bf R10: 00007fd37ec00000 R11: 0000000000000246 R12: 000000000004b167 R13: 00007ffe9d11eed0 R14: 0000000000000032 R15: ffffffffffffffff rcu: rcu_preempt kthread starved for 10495 jiffies! g51105 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:24176 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:312 [inline] RIP: 0010:smp_call_function_many_cond+0x1860/0x29d0 kernel/smp.c:856 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 39 18 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 e4 13 0c 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 c8 13 RSP: 0018:ffffc90000117700 EFLAGS: 00000293 RAX: ffffffff81877898 RBX: 1ffff110171288e9 RCX: ffff88801cec5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900001178e0 R08: ffffffff81877867 R09: 1ffffffff27f4d08 R10: dffffc0000000000 R11: fffffbfff27f4d09 R12: dffffc0000000000 R13: ffff8880b8944748 R14: ffff8880b883fb00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f070fa656c0 CR3: 000000000e534000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:833 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog