rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=de5c/1/0x4000000000000000 softirq=79431/79431 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=61889, q=173 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15678 Comm: syz.0.3084 Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:kasan_byte_accessible+0x1b/0x30 mm/kasan/generic.c:202 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 0f b6 04 07 3c 08 0f 92 c0 5b 40 ed fe cc 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 RSP: 0018:ffffc90000a08ba0 EFLAGS: 00000093 RAX: 0000000000000001 RBX: ffffffff8b7b4b2e RCX: 85e519040e240f00 RDX: 0000000000000000 RSI: ffffffff8b7b4b2e RDI: 1ffff1100a5d5860 RBP: ffffffff8999ce54 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8999cd90 R12: 0000000000000000 R13: ffff888052eac300 R14: ffff888052eac300 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125d21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32c21ffc CR3: 000000007d1d0000 CR4: 0000000000350ef0 Call Trace: __kasan_check_byte+0x12/0x40 mm/kasan/common.c:567 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:_compound_head include/linux/page-flags.h:284 [inline] RIP: 0010:__folio_rmap_sanity_checks+0xf8/0x7d0 include/linux/rmap.h:426 Code: e7 ad ff bf 01 00 00 00 89 ee e8 33 ec ad ff 85 ed 49 bd 00 00 00 00 00 fc ff df 0f 8e b3 03 00 00 e8 dc e7 ad ff 4d 8d 67 08 <4c> 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 62 52 11 00 RSP: 0018:ffffc90004d1f510 EFLAGS: 00000293 RAX: ffffffff8211c3d4 RBX: ffffea0001a71500 RCX: ffff888067f71e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffea0001a71507 R09: 1ffffd400034e2a0 R10: dffffc0000000000 R11: fffff9400034e2a1 R12: ffffea0001a71508 R13: dffffc0000000000 R14: 8000000069c54000 R15: ffffea0001a71500 __folio_remove_rmap mm/rmap.c:1694 [inline] folio_remove_rmap_ptes+0x3b/0xaf0 mm/rmap.c:1804 zap_present_folio_ptes mm/memory.c:1523 [inline] zap_present_ptes mm/memory.c:1581 [inline] do_zap_pte_range mm/memory.c:1682 [inline] zap_pte_range mm/memory.c:1726 [inline] zap_pmd_range mm/memory.c:1818 [inline] zap_pud_range mm/memory.c:1847 [inline] zap_p4d_range mm/memory.c:1868 [inline] unmap_page_range+0x1f7f/0x4370 mm/memory.c:1889 unmap_single_vma mm/memory.c:1932 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1976 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0x118/0x430 kernel/fork.c:1129 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe13458ebe9 Code: Unable to access opcode bytes at 0x7fe13458ebbf. RSP: 002b:00007ffd11d1dca8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe13458ebe9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd11d1dd0c R08: 0000000411d1dd9f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000001ff R13: 00000000000927c0 R14: 00000000000765ff R15: 00007ffd11d1dd60 rcu: rcu_preempt kthread starved for 10500 jiffies! g61889 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 12562 Comm: syz-executor Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 5e 0b 00 eb e4 44 RSP: 0018:ffffc9000b247540 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170e7f61 RCX: ffff88807cf20000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000b2476c0 R08: ffffffff8fa34537 R09: 1ffffffff1f468a6 R10: dffffc0000000000 R11: fffffbfff1f468a7 R12: ffff8880b873fb08 R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001 FS: 0000555593a6f500(0000) GS:ffff888125c21000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33123ffc CR3: 000000004cafa000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451 dup_mmap+0x15a0/0x1ac0 mm/mmap.c:1873 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd00f785453 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffcc221f348 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd00f785453 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555593a6f7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000076d9d R15: 00007ffcc221f4e0