rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 3-....: (2 ticks this GP) idle=c2e4/1/0x4000000000000000 softirq=29076/29076 fqs=5 rcu: hardirqs softirqs csw/system rcu: number: 21 1 37 rcu: cputime: 0 0 1 ==> 51540(ms) rcu: (detected by 0, t=10504 jiffies, g=32517, q=5265 ncpus=4) Sending NMI from CPU 0 to CPUs 3: NMI backtrace for cpu 3 CPU: 3 UID: 0 PID: 10620 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:get_current arch/x86/include/asm/current.h:23 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xf/0x70 kernel/kcov.c:216 Code: 00 00 00 5b e9 42 32 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 05 1e 5a 12 48 8b 34 24 <65> 48 8b 15 e1 1d 5a 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 RSP: 0000:ffffc90000708e90 EFLAGS: 00000002 RAX: 0000000000010001 RBX: dffffc0000000000 RCX: ffffffff81f6128f RDX: 18c8402172e4b010 RSI: ffffffff81f6129d RDI: ffff88802f7dca80 RBP: 18c8402172e4b010 R08: 0000000000000006 R09: 18c8402498e5ef64 R10: 18c8402172e4b010 R11: 0000000000000000 R12: ffff88802d15d300 R13: 0000000000000001 R14: ffff88806a728540 R15: 18c8402498e5ef64 FS: 00007fe09853e880(0000) GS:ffff8880d60d8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562e4945ff38 CR3: 0000000040c09000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1998 [inline] __hrtimer_run_queues+0x29d/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline] RIP: 0010:unwind_next_frame+0x157d/0x2090 arch/x86/kernel/unwind_orc.c:677 Code: 0f 84 f3 ed ff ff 48 89 ef e8 9f e2 ff ff 49 8d 7d 40 48 89 fa 48 89 c5 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 84 17 fa ff ff e8 a8 74 c2 00 e9 0d fa ff ff 48 b8 00 00 00 00 RSP: 0000:ffffc90006ecf1c8 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff91d1e898 RDX: 1ffff92000dd9e4f RSI: ffffc90006ecfe78 RDI: ffffc90006ecf278 RBP: ffffc90006ecff48 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 000000000001614c R12: ffffc90006ecf288 R13: ffffc90006ecf238 R14: ffffc90006ecfea8 R15: ffffc90006ecf26c arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __set_page_owner+0x8c/0x540 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509 vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544 folio_prealloc mm/memory.c:1209 [inline] wp_page_copy mm/memory.c:3875 [inline] do_wp_page+0x1ee1/0x4350 mm/memory.c:4336 handle_pte_fault mm/memory.c:6395 [inline] __handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fe097eb5b37 Code: e0 f8 48 3b 04 07 0f 85 a9 00 00 00 f3 0f 6f 47 10 48 8b 57 18 66 48 0f 7e c0 48 3b 78 18 75 7b 48 3b 7a 10 75 75 48 8b 77 10 <48> 89 50 18 66 0f d6 42 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 RSP: 002b:00007ffc273b7b50 EFLAGS: 00010246 RAX: 0000562e4945ff20 RBX: 0000562e49462550 RCX: 0000000000000121 RDX: 00007fe097ff1c30 RSI: 0000562e4945ff20 RDI: 0000562e49462570 RBP: 0000000000000140 R08: 00000000000189a0 R09: 0000562e4944bde0 R10: 0000000000000120 R11: 00000000ffffffff R12: 00007fe097ff1ad0 R13: 0000562b2ba02982 R14: 0000000562e49462 R15: 00007fe097ff1ac0 rcu: rcu_preempt kthread starved for 5139 jiffies! g32517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=2 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:28824 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 2: NMI backtrace for cpu 2 CPU: 2 UID: 0 PID: 6948 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x58e/0x1870 kernel/smp.c:912 Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 44 9a 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31 RSP: 0018:ffffc90004227588 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff81fdc802 RDX: ffff888030560000 RSI: ffffffff81fdc7dc RDI: ffff888030560000 RBP: ffff88806a743500 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed100d4e86a1 R14: 0000000000000001 R15: ffff88806a63c880 FS: 0000000000000000(0000) GS:ffff8880d5fd8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5e94655490 CR3: 000000000e994000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077 kvm_flush_tlb_multi+0x22e/0x370 arch/x86/kernel/kvm.c:688 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline] tlb_flush_mmu mm/mmu_gather.c:423 [inline] tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549 exit_mmap+0x454/0xa00 mm/mmap.c:1313 __mmput+0x12a/0x410 kernel/fork.c:1187 mmput+0x67/0x80 kernel/fork.c:1210 exit_mm kernel/exit.c:615 [inline] do_exit+0x8b1/0x2ae0 kernel/exit.c:997 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8e1195e84e Code: Unable to access opcode bytes at 0x7f8e1195e824. RSP: 002b:00007fff23b83328 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000555586462500 RCX: 00007f8e1195e84e RDX: 0000000000000030 RSI: 00007fff23b83420 RDI: 00000000000000f9 RBP: 00007fff23b833cc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000014a R13: 00000000000927c0 R14: 0000000000052535 R15: 00007fff23b83420