rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8103/1:b..l rcu: (detected by 1, t=10502 jiffies, g=19493, q=269 ncpus=2) task:syz.1.986 state:R running task stack:25600 pid:8103 tgid:8092 ppid:5814 task_flags:0x40044c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6943 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:1761 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0xec7/0x43a0 mm/memory.c:1894 unmap_single_vma+0x194/0x2b0 mm/memory.c:1940 unmap_vmas+0x22f/0x490 mm/memory.c:1984 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 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: 0033:0x7fe0e018cda9 RSP: 002b:00007fe0ddfd50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fe0e03a6088 RCX: 00007fe0e018cda9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe0e03a6088 RBP: 00007fe0e03a6080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0e03a608c R13: 0000000000000000 R14: 00007ffccf78c910 R15: 00007ffccf78c9f8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g19493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=9440 rcu: rcu_preempt kthread starved for 10502 jiffies! g19493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27168 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8126 Comm: syz.4.1001 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0x20 kernel/kcov.c:300 Code: bf 06 00 00 00 e9 b8 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 <40> 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 86 fe ff ff 66 0f 1f 44 RSP: 0018:ffffc90000007e28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81a710c6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 000000000003d94c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000004 R12: ffff88805b874340 R13: ffff8880b862c880 R14: ffff8880b862c680 R15: ffffffff8969f2d0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fada5b15f98 CR3: 0000000060164000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline] __run_hrtimer kernel/time/hrtimer.c:1798 [inline] __hrtimer_run_queues+0x816/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 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:_compound_head include/linux/page-flags.h:245 [inline] RIP: 0010:zap_present_ptes mm/memory.c:1577 [inline] RIP: 0010:do_zap_pte_range mm/memory.c:1698 [inline] RIP: 0010:zap_pte_range mm/memory.c:1740 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1823 [inline] RIP: 0010:zap_pud_range mm/memory.c:1852 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1873 [inline] RIP: 0010:unmap_page_range+0xc56/0x43a0 mm/memory.c:1894 Code: 70 0d b6 ff 48 8b 44 24 58 48 8d 78 08 48 89 f8 48 c1 e8 03 42 80 3c 38 00 0f 85 d3 36 00 00 48 8b 44 24 58 31 ff 48 8b 68 08 <48> 89 eb 83 e3 01 48 89 de e8 6c 08 b6 ff 48 85 db 0f 85 e9 18 00 RSP: 0018:ffffc90003767628 EFLAGS: 00000246 RAX: ffffea0001836100 RBX: ffff888079892800 RCX: ffffffff8203abae RDX: ffff888026a44880 RSI: ffffffff8203c4a0 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000006 R09: 00000000000137fd R10: 0000000000060d84 R11: 0000000000000003 R12: 000000000000010a R13: ffff8880306527b0 R14: 0000000000000001 R15: dffffc0000000000 unmap_single_vma+0x194/0x2b0 mm/memory.c:1940 unmap_vmas+0x22f/0x490 mm/memory.c:1984 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 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: 0033:0x7fada4d8cda9 Code: Unable to access opcode bytes at 0x7fada4d8cd7f. RSP: 002b:00007fada5b160e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fada4fa5fa8 RCX: 00007fada4d8cda9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fada4fa5fa8 RBP: 00007fada4fa5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fada4fa5fac R13: 0000000000000000 R14: 00007ffee9f8fef0 R15: 00007ffee9f8ffd8