rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6632/1:b..l (detected by 1, t=10502 jiffies, g=323225, q=2053) task:syz-executor.1 state:R running task stack:23688 pid: 6632 ppid: 6548 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6459 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __raw_read_unlock include/linux/rwlock_api_smp.h:227 [inline] _raw_read_unlock+0x36/0x40 kernel/locking/spinlock.c:260 zap_pid_ns_processes+0x271/0x660 kernel/pid_namespace.c:207 find_child_reaper kernel/exit.c:542 [inline] forget_original_parent kernel/exit.c:631 [inline] exit_notify kernel/exit.c:668 [inline] do_exit+0x234c/0x2a30 kernel/exit.c:845 do_group_exit+0x125/0x310 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f126e104a39 RSP: 002b:00007f126e73bc58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f126e104a39 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 000000000000002e R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007f126e15eef5 R13: 000000000000000b R14: 0000000000000001 R15: 00007f126e73be40 rcu: rcu_preempt kthread timer wakeup didn't happen for 1046 jiffies! g323225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=204912 rcu: rcu_preempt kthread starved for 1047 jiffies! g323225 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11800 Comm: syz-executor.1 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0x0/0xc0 kernel/locking/lockdep.c:5073 Code: 89 ee 48 c7 c7 60 fe 8b 89 e8 77 16 be ff 48 c7 c7 c0 fe 8b 89 e8 6b 16 be ff e8 31 dd cc ff 31 c0 5d c3 0f 1f 80 00 00 00 00 <53> 48 89 fb 48 83 ec 08 48 39 77 10 74 6a 66 f7 47 22 f0 ff 74 5a RSP: 0018:ffffc90000007d90 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8b981a60 RDI: ffff888172040a20 RBP: ffffffff8b981a60 R08: 0000000000000000 R09: ffff8880b9c32a0b R10: ffffed1017386541 R11: 0000000000000000 R12: ffff888172040000 R13: ffff888172040a20 R14: 00000000ffffffff R15: ffff888172040a20 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c019810060 CR3: 000000007292a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5368 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5668 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5636 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] ktime_get_update_offsets_now+0x93/0x5c0 kernel/time/timekeeping.c:2297 hrtimer_update_base kernel/time/hrtimer.c:631 [inline] hrtimer_interrupt+0x142/0x790 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:perf_trace_lock_acquire+0xa1/0x550 include/trace/events/lock.h:13 Code: f2 c7 40 08 00 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 48 8d 46 18 48 89 85 48 ff ff ff 48 c1 e8 03 80 3c 10 00 <0f> 85 4d 03 00 00 49 8b 7e 18 48 c7 c0 60 03 8c 89 48 85 ff 48 0f RSP: 0018:ffffc900265af510 EFLAGS: 00000246 RAX: 1ffffffff1730367 RBX: 1ffff92004cb5ec5 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff8b981b20 RDI: ffffffff8b87ef20 RBP: ffffc900265af5f8 R08: 0000000000000002 R09: 0000000000000000 R10: fffffbfff1adceb2 R11: 0000000000000000 R12: 0000000000000002 R13: ffffffff8b87ef20 R14: ffffffff8b981b20 R15: ffffc900265af5d0 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x416/0x510 kernel/locking/lockdep.c:5596 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] lock_page_memcg+0x66/0x7d0 mm/memcontrol.c:1979 page_remove_rmap+0x25/0x1480 mm/rmap.c:1348 zap_pte_range mm/memory.c:1362 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xed5/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x630 mm/mmap.c:3171 __mmput+0x122/0x4b0 kernel/fork.c:1115 mmput+0x58/0x60 kernel/fork.c:1136 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x21d0 kernel/signal.c:2855 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f126e104a39 Code: Unable to access opcode bytes at RIP 0x7f126e104a0f. RSP: 002b:00007f126b67a218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f126e207f68 RCX: 00007f126e104a39 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f126e207f68 RBP: 00007f126e207f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f126e207f6c R13: 00007f126e73bb2f R14: 00007f126b67a300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 89 ee mov %ebp,%esi 2: 48 c7 c7 60 fe 8b 89 mov $0xffffffff898bfe60,%rdi 9: e8 77 16 be ff callq 0xffbe1685 e: 48 c7 c7 c0 fe 8b 89 mov $0xffffffff898bfec0,%rdi 15: e8 6b 16 be ff callq 0xffbe1685 1a: e8 31 dd cc ff callq 0xffccdd50 1f: 31 c0 xor %eax,%eax 21: 5d pop %rbp 22: c3 retq 23: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) * 2a: 53 push %rbx <-- trapping instruction 2b: 48 89 fb mov %rdi,%rbx 2e: 48 83 ec 08 sub $0x8,%rsp 32: 48 39 77 10 cmp %rsi,0x10(%rdi) 36: 74 6a je 0xa2 38: 66 f7 47 22 f0 ff testw $0xfff0,0x22(%rdi) 3e: 74 5a je 0x9a