rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10499 ticks this GP) idle=37f/1/0x4000000000000000 softirq=11868/11868 fqs=4 (t=10501 jiffies g=13769 q=300 ncpus=2) rcu: rcu_preempt kthread starved for 10494 jiffies! g13769 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28680 pid: 16 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5106 [inline] __schedule+0xa9a/0x4cc0 kernel/sched/core.c:6421 schedule+0xd2/0x1f0 kernel/sched/core.c:6493 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1907 rcu_gp_fqs_loop+0x1c0/0x840 kernel/rcu/tree.c:2078 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2267 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 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: 5311 Comm: syz-executor.4 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c RSP: 0018:ffffc90014dc7c08 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff8880b9d3ae40 RCX: 1ffffffff1b73199 RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd RBP: ffff8880b9c3ae54 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81807158 R11: 0000000000000000 R12: ffffed10173a75ca R13: ffff8880b9d3ae54 R14: dffffc0000000000 R15: ffff8880b9c3ae40 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d04f000 CR3: 000000007c805000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline] __pv_queued_spin_lock_slowpath+0x6d8/0xb50 kernel/locking/qspinlock.c:476 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:354 [inline] task_lock include/linux/sched/task.h:170 [inline] mm_update_next_owner+0x21a/0x7a0 kernel/exit.c:457 exit_mm kernel/exit.c:509 [inline] do_exit+0xa0a/0x2a00 kernel/exit.c:782 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934 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: 0033:0x7fdb080890e9 Code: Unable to access opcode bytes at RIP 0x7fdb080890bf. RSP: 002b:00007fff7d369768 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 00007fdb080890e9 RDX: 00007fdb0803bd2b RSI: ffffffffffffffb8 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00000000079a5169 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff7d369850 NMI backtrace for cpu 1 CPU: 1 PID: 5316 Comm: syz-executor.4 Not tainted 5.18.0-rc3-next-20220422-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x262/0x3f0 kernel/rcu/tree_stall.h:369 print_cpu_stall kernel/rcu/tree_stall.h:665 [inline] check_cpu_stall kernel/rcu/tree_stall.h:749 [inline] rcu_pending kernel/rcu/tree.c:4068 [inline] rcu_sched_clock_irq.cold+0x144/0x8fc kernel/rcu/tree.c:2755 update_process_times+0x16d/0x200 kernel/time/timer.c:1811 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:243 tick_sched_timer+0xee/0x120 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:kvm_wait+0x98/0x100 arch/x86/kernel/kvm.c:1058 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 63 0f b6 07 40 38 c6 74 35 48 83 c4 10 c3 c3 e8 23 91 4b 00 eb 07 0f 00 2d da b1 94 08 fb f4 <48> 83 c4 10 c3 89 74 24 0c 48 89 3c 24 e8 56 8f 4b 00 8b 74 24 0c RSP: 0018:ffffc90000de0338 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199 RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd RBP: ffff88801b4761c8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81807158 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed100368ec39 R14: 0000000000000001 R15: ffff8880b9d3ae40 pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8c7/0xb50 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:354 [inline] task_lock include/linux/sched/task.h:170 [inline] __get_task_comm+0x23/0x50 fs/exec.c:1219 __set_page_owner_handle mm/page_owner.c:174 [inline] __set_page_owner+0x253/0x380 mm/page_owner.c:192 prep_new_page mm/page_alloc.c:2394 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273 alloc_slab_page mm/slub.c:1797 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x985/0xd90 mm/slub.c:3002 kmem_cache_alloc_bulk+0x21c/0x720 mm/slub.c:3704 napi_skb_cache_get+0xeb/0x170 net/core/skbuff.c:176 __alloc_skb+0x9b/0x340 net/core/skbuff.c:412 __napi_alloc_skb+0x70/0x310 net/core/skbuff.c:568 napi_alloc_skb include/linux/skbuff.h:3194 [inline] page_to_skb+0x17d/0xc10 drivers/net/virtio_net.c:464 receive_mergeable drivers/net/virtio_net.c:1066 [inline] receive_buf+0xdc5/0x54c0 drivers/net/virtio_net.c:1205 virtnet_receive drivers/net/virtio_net.c:1500 [inline] virtnet_poll+0x5cd/0x11a0 drivers/net/virtio_net.c:1609 __napi_poll+0xb3/0x6e0 net/core/dev.c:6443 napi_poll net/core/dev.c:6510 [inline] net_rx_action+0x8ec/0xc60 net/core/dev.c:6597 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 common_interrupt+0xa9/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:640 RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:210 Code: 82 88 15 00 00 83 f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 0f 1f 00 41 55 41 54 49 89 fc 55 48 bd eb 83 b5 80 46 86 c8 61 RSP: 0018:ffffc90014fd7490 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000001 RCX: ffffc90005171000 RDX: 0000000000040000 RSI: ffffffff83faa507 RDI: ffff888013350eb8 RBP: ffff888013350ea8 R08: 0000000000000001 R09: ffff888013350eb7 R10: ffffed100266a1d6 R11: 0000000000000001 R12: 000000000000000e R13: 0000000000000010 R14: ffff888013350e88 R15: 0000000000000007 strscpy_pad+0x67/0x70 lib/string_helpers.c:794 __get_task_comm+0x35/0x50 fs/exec.c:1221 __set_page_owner_handle mm/page_owner.c:174 [inline] __set_page_owner+0x253/0x380 mm/page_owner.c:192 prep_new_page mm/page_alloc.c:2394 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4135 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5356 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2273 folio_alloc+0x1c/0x70 mm/mempolicy.c:2283 filemap_alloc_folio mm/filemap.c:996 [inline] __filemap_get_folio+0x614/0xf00 mm/filemap.c:1992 pagecache_get_page+0x2e/0x290 mm/folio-compat.c:126 ext4_da_write_begin+0x3bb/0xb40 fs/ext4/inode.c:2967 generic_perform_write+0x249/0x560 mm/filemap.c:3792 ext4_buffered_write_iter+0x15b/0x330 fs/ext4/file.c:270 ext4_file_write_iter+0x43c/0x1510 fs/ext4/file.c:679 call_write_iter include/linux/fs.h:2059 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 ksys_write+0x127/0x250 fs/read_write.c:644 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: 0033:0x7fdb080890e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdb06ffe168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fdb0819bf60 RCX: 00007fdb080890e9 RDX: 00000000fffffe5e RSI: 0000000020000080 RDI: 0000000000000005 RBP: 00007fdb080e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff7d36952f R14: 00007fdb06ffe300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: fa cli 1: 83 e2 07 and $0x7,%edx 4: 38 d0 cmp %dl,%al 6: 7f 04 jg 0xc 8: 84 c0 test %al,%al a: 75 63 jne 0x6f c: 0f b6 07 movzbl (%rdi),%eax f: 40 38 c6 cmp %al,%sil 12: 74 35 je 0x49 14: 48 83 c4 10 add $0x10,%rsp 18: c3 retq 19: c3 retq 1a: e8 23 91 4b 00 callq 0x4b9142 1f: eb 07 jmp 0x28 21: 0f 00 2d da b1 94 08 verw 0x894b1da(%rip) # 0x894b202 28: fb sti 29: f4 hlt * 2a: 48 83 c4 10 add $0x10,%rsp <-- trapping instruction 2e: c3 retq 2f: 89 74 24 0c mov %esi,0xc(%rsp) 33: 48 89 3c 24 mov %rdi,(%rsp) 37: e8 56 8f 4b 00 callq 0x4b8f92 3c: 8b 74 24 0c mov 0xc(%rsp),%esi