rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=6144/1/0x4000000000000000 softirq=21880/21880 fqs=1 rcu: (detected by 0, t=10503 jiffies, g=15221, q=584 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7716 Comm: syz.4.441 Not tainted 6.13.0-rc7-syzkaller-00189-g595523945be0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__lock_acquire+0x2ce/0x3c40 kernel/locking/lockdep.c:5160 Code: ea 03 66 25 00 e0 44 09 f0 66 41 89 47 20 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 85 8e 2b 00 00 48 8b 84 24 30 01 00 00 <49> 89 47 08 49 8d 47 10 48 89 c2 48 89 44 24 50 48 b8 00 00 00 00 RSP: 0018:ffffc90000a18ab0 EFLAGS: 00000046 RAX: ffffffff84a5c159 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 1ffff1100b6c75ef RSI: 1ffff1100b6c75ed RDI: ffff88805b63af78 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000001 R12: ffffffff9aaeee60 R13: ffff88805b63a440 R14: 0000000000000000 R15: ffff88805b63af70 FS: 00007f7c53b336c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c149b14300 CR3: 00000000355b0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_activate+0x149/0x4a0 lib/debugobjects.c:818 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 da 22 4a f6 48 89 df e8 32 a2 4a f6 e8 1d 1d 75 f6 fb bf 01 00 00 00 32 87 3b f6 65 8b 05 f3 30 d7 74 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc9000443f3d8 EFLAGS: 00000202 RAX: 0000000000004185 RBX: ffff88805385e5a0 RCX: 1ffffffff2dcd3e8 RDX: 0000000000000000 RSI: ffffffff8b6cd9e0 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff2dca79f R10: ffffffff96e53cff R11: 0000000000000002 R12: ffff88805385e598 R13: ffffc9000443f448 R14: 0000000000000cc0 R15: ffff88814996b180 spin_unlock_irq include/linux/spinlock.h:401 [inline] shmem_add_to_page_cache+0x601/0x9b0 mm/shmem.c:835 shmem_alloc_and_add_folio+0x65f/0xc00 mm/shmem.c:1864 shmem_get_folio_gfp+0x689/0x1530 mm/shmem.c:2358 shmem_fault+0x200/0xae0 mm/shmem.c:2559 __do_fault+0x10a/0x490 mm/memory.c:4907 do_read_fault mm/memory.c:5322 [inline] do_fault mm/memory.c:5456 [inline] do_pte_missing+0xebd/0x3e00 mm/memory.c:3979 handle_pte_fault mm/memory.c:5801 [inline] __handle_mm_fault+0x103c/0x2a40 mm/memory.c:5944 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6112 faultin_page mm/gup.c:1196 [inline] __get_user_pages+0x8d9/0x3b50 mm/gup.c:1494 populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1932 __mm_populate+0x1d6/0x380 mm/gup.c:2035 mm_populate include/linux/mm.h:3397 [inline] vm_mmap_pgoff+0x293/0x360 mm/util.c:580 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:546 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 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: 0033:0x7f7c52d85d29 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:00007f7c53b33038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f7c52f75fa0 RCX: 00007f7c52d85d29 RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f7c52e01b08 R08: ffffffffffffffff R09: 000000006a855000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7c52f75fa0 R15: 00007ffe07a1c858 rcu: rcu_preempt kthread starved for 10496 jiffies! g15221 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:27600 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3458 Comm: kworker/u8:6 Not tainted 6.13.0-rc7-syzkaller-00189-g595523945be0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246 Code: cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 0f bb 69 7e <65> 8b 05 10 bb 69 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 RSP: 0018:ffffc9000c297990 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b8744a40 RCX: ffffffff818e191c RDX: ffff888032c18000 RSI: 0000000000000000 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: 00007ffbd9c62b47 CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 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