rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (2 ticks this GP) idle=869c/1/0x4000000000000000 softirq=55908/55908 fqs=0 rcu: (t=13364 jiffies g=25205 q=892 ncpus=1) rcu: rcu_preempt kthread timer wakeup didn't happen for 13363 jiffies! g25205 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=7906 rcu: rcu_preempt kthread starved for 13364 jiffies! g25205 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:28808 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+0x70e/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 CPU: 0 UID: 0 PID: 5047 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:unwind_next_frame+0x4ef/0x2390 arch/x86/kernel/unwind_orc.c:512 Code: 62 05 48 89 f0 48 c1 e8 03 48 89 44 24 40 0f b6 04 28 84 c0 48 89 54 24 08 48 89 34 24 0f 85 4d 18 00 00 4c 89 e0 48 c1 e8 03 <0f> b6 04 28 84 c0 0f 85 63 18 00 00 0f b7 1e c1 eb 0b 80 e3 01 48 RSP: 0018:ffffc9000d17ead8 EFLAGS: 00000a03 RAX: 1ffffffff207fc2a RBX: ffffffff8fbfba70 RCX: ffffffff8fbfba74 RDX: ffffffff903fe152 RSI: ffffffff903fe156 RDI: ffffffff8be349a0 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8172c195 R10: ffffc9000d17ebf8 R11: ffffffff81ac3ae0 R12: ffffffff903fe157 R13: ffffc9000d17ebf8 R14: ffffc9000d17eba8 R15: ffffffff8172c195 FS: 00007f8248e11740(0000) GS:ffff88808d20c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffee2f1a300 CR3: 000000004304c000 CR4: 0000000000352ef0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 pagetable_alloc_noprof include/linux/mm.h:2881 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:75 [inline] pte_alloc_one+0x21/0x170 arch/x86/mm/pgtable.c:18 __pte_alloc+0x25/0x1a0 mm/memory.c:452 copy_pte_range mm/memory.c:1107 [inline] copy_pmd_range+0x6a91/0x71d0 mm/memory.c:1261 copy_pud_range mm/memory.c:1298 [inline] copy_p4d_range mm/memory.c:1322 [inline] copy_page_range+0xc14/0x1270 mm/memory.c:1410 dup_mmap+0xf57/0x1ac0 mm/mmap.c:1834 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: 0033:0x7f8248ee5636 Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 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 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffee2ef9a10 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffee2ef9a18 RCX: 00007f8248ee5636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffee2f19f60 R08: 0000000000000000 R09: 0000000000000001 R10: 00007f8248e11a10 R11: 0000000000000246 R12: 00007ffee2ef9b50 R13: 0000000000000000 R14: 0000000000000000 R15: 000055683f7adac0