rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=bcac/1/0x4000000000000000 softirq=12358/12358 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=11817, q=1014 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5925 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lock_acquire+0x6a/0x410 kernel/locking/lockdep.c:5722 Code: 24 c0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 60 b3 8a b5 41 48 c7 44 24 68 cd 31 59 8c 48 c7 44 24 70 00 f9 66 81 <4c> 8d 64 24 60 49 c1 ec 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 04 RSP: 0018:ffffc900001f0b40 EFLAGS: 00000082 RAX: b433d56b94522900 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802a05d300 RBP: ffffc900001f0c48 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffff88802a05d340 R13: ffff88802a05d300 R14: ffff88807472c000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003c80 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: __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+0xc5/0xc80 net/sched/sch_taprio.c:940 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:kasan_check_range+0x1bd/0x290 mm/kasan/generic.c:-1 Code: 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 49 ff cc 75 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 45 84 ff 75 61 41 f7 c7 00 ff 00 RSP: 0018:ffffc90003347888 EFLAGS: 00000256 RAX: ffffffff81b8ba01 RBX: 0000000000000000 RCX: ffffffff81b8bacd RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0001b89134 RBP: ffffc90003347a00 R08: ffffea0001b89137 R09: 1ffffd4000371226 R10: dffffc0000000000 R11: fffff94000371227 R12: 0000000000000001 R13: 0000000000000000 R14: fffff94000371227 R15: 1ffffd4000371226 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:1110 [inline] folio_put_testzero include/linux/mm.h:1116 [inline] release_pages+0x2ed/0x2220 mm/swap.c:992 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x368/0x4f0 mm/mmu_gather.c:300 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:392 exit_mmap+0x3f0/0xb50 mm/mmap.c:3315 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f059f78f749 Code: Unable to access opcode bytes at 0x7f059f78f71f. RSP: 002b:00007ffc7010ff28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f059f78f749 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 000000097011001f R09: 00007f059f9b4280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f059f9b4280 R14: 0000000000000003 R15: 00007ffc7010ffe0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g11817 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=6653 rcu: rcu_preempt kthread starved for 10505 jiffies! g11817 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:I stack:26728 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5925 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:kasan_check_range+0x1be/0x290 mm/kasan/generic.c:-1 Code: 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 49 ff cc 75 ee 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 45 84 ff 75 61 41 f7 c7 00 ff 00 00 RSP: 0018:ffffc900001f0b10 EFLAGS: 00000056 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81677b7b RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e4a2128 RBP: ffffc900001f0c60 R08: ffffffff8e4a212f R09: 1ffffffff1c94425 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 0000000000000001 R13: dffffc0000000000 R14: fffffbfff1c94426 R15: 1ffffffff1c94425 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003c80 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:504 [inline] cpu_online include/linux/cpumask.h:1082 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xab/0x8b0 kernel/locking/lockdep.c:5765 rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] advance_sched+0xb29/0xc80 net/sched/sch_taprio.c:1003 __run_hrtimer kernel/time/hrtimer.c:1750 [inline] __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:kasan_check_range+0x1bd/0x290 mm/kasan/generic.c:-1 Code: 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 49 ff cc 75 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 45 84 ff 75 61 41 f7 c7 00 ff 00 RSP: 0018:ffffc90003347888 EFLAGS: 00000256 RAX: ffffffff81b8ba01 RBX: 0000000000000000 RCX: ffffffff81b8bacd RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffea0001b89134 RBP: ffffc90003347a00 R08: ffffea0001b89137 R09: 1ffffd4000371226 R10: dffffc0000000000 R11: fffff94000371227 R12: 0000000000000001 R13: 0000000000000000 R14: fffff94000371227 R15: 1ffffd4000371226 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:1110 [inline] folio_put_testzero include/linux/mm.h:1116 [inline] release_pages+0x2ed/0x2220 mm/swap.c:992 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x368/0x4f0 mm/mmu_gather.c:300 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:392 exit_mmap+0x3f0/0xb50 mm/mmap.c:3315 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f059f78f749 Code: Unable to access opcode bytes at 0x7f059f78f71f. RSP: 002b:00007ffc7010ff28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f059f78f749 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 000000097011001f R09: 00007f059f9b4280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f059f9b4280 R14: 0000000000000003 R15: 00007ffc7010ffe0