rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=14b/1/0x4000000000000000 softirq=29917/29922 fqs=1 (t=10500 jiffies g=34561 q=170 ncpus=2) rcu: rcu_preempt kthread starved for 10498 jiffies! g34561 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:29264 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: 10274 Comm: syz-executor.5 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:ffffc90000007b80 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199 RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd RBP: ffff888077358c98 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81807158 R11: 0000000000000000 R12: 0000000000000000 R13: ffffed100ee6b193 R14: 0000000000000001 R15: ffff8880b9c3ae40 FS: 00007f2179cd7700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002025e000 CR3: 000000001d2f6000 CR4: 00000000003506f0 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_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] tcp_delack_timer+0x26/0x320 net/ipv4/tcp_timer.c:342 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1444 expire_timers kernel/time/timer.c:1489 [inline] __run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1760 __run_timers kernel/time/timer.c:1738 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1773 __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 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:check_kcov_mode+0x7/0x40 kernel/kcov.c:166 Code: 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 13 90 4c 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 65 8b 05 e9 54 88 7e <89> c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b RSP: 0018:ffffc9000f8e7888 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffff88801c020000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff88801f4ddbbf R10: ffffffff8135cab0 R11: 0000000000000000 R12: ffffc9000f8e7938 R13: 000000002025e000 R14: ffff8880166c5420 R15: ffff88801f4ddb00 write_comp_data kernel/kcov.c:221 [inline] __sanitizer_cov_trace_const_cmp8+0x1d/0x70 kernel/kcov.c:294 __pkru_allows_pkey arch/x86/include/asm/pgtable.h:1394 [inline] arch_vma_access_permitted arch/x86/include/asm/mmu_context.h:216 [inline] arch_vma_access_permitted arch/x86/include/asm/mmu_context.h:207 [inline] access_error arch/x86/mm/fault.c:1106 [inline] do_user_addr_fault+0xb70/0x11c0 arch/x86/mm/fault.c:1379 handle_page_fault arch/x86/mm/fault.c:1484 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1540 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:fault_in_readable+0x175/0x290 mm/gup.c:1796 Code: e4 c9 ff 49 39 dd 0f 84 06 01 00 00 45 31 f6 eb 11 e8 7f e4 c9 ff 48 81 c3 00 10 00 00 4c 39 eb 74 1d e8 6e e4 c9 ff 45 89 f7 <8a> 03 31 ff 44 89 fe 88 44 24 28 e8 7b e6 c9 ff 45 85 ff 74 d2 e8 RSP: 0018:ffffc9000f8e79e0 EFLAGS: 00050246 RAX: 0000000000040000 RBX: 000000002025e000 RCX: ffffc90003443000 RDX: 0000000000040000 RSI: ffffffff81b03ab2 RDI: 0000000000000003 RBP: 000000002025d0c0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81b03a56 R11: 0000000000000000 R12: 0000000000001000 R13: 000000002025f000 R14: 0000000000000000 R15: 0000000000000000 fault_in_iov_iter_readable lib/iov_iter.c:458 [inline] fault_in_iov_iter_readable+0x11f/0x1f0 lib/iov_iter.c:444 generic_perform_write+0x19e/0x560 mm/filemap.c:3782 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: 0033:0x7f2178a890e9 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:00007f2179cd7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2178b9bf60 RCX: 00007f2178a890e9 RDX: 000000000208e24b RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f2178ae308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd8e2e7c1f R14: 00007f2179cd7300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 10260 Comm: syz-executor.2 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:ffffc90000ddfee0 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 1ffffffff1b73199 RDX: 0000000000000000 RSI: ffffffff81807171 RDI: ffffffff8134dffd RBP: ffff88801b128948 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81807158 R11: 0000000000000001 R12: 0000000000000000 R13: ffffed1003625129 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 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3239 skb_clone+0x170/0x3c0 net/core/skbuff.c:1520 dev_queue_xmit_nit+0x393/0xb20 net/core/dev.c:2263 xmit_one net/core/dev.c:3532 [inline] dev_hard_start_xmit+0xad/0x920 net/core/dev.c:3553 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3764 [inline] __dev_queue_xmit+0x1572/0x3b10 net/core/dev.c:4173 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14df/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x32/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x8fe/0x1c00 net/ipv4/ip_output.c:532 __tcp_transmit_skb+0x190e/0x38b0 net/ipv4/tcp_output.c:1402 tcp_transmit_skb net/ipv4/tcp_output.c:1420 [inline] tcp_write_xmit+0xd92/0x60e0 net/ipv4/tcp_output.c:2690 tcp_tsq_write net/ipv4/tcp_output.c:1021 [inline] tcp_tsq_write+0x20c/0x360 net/ipv4/tcp_output.c:1008 tcp_tsq_handler+0x8e/0x200 net/ipv4/tcp_output.c:1030 tcp_tasklet_func+0x2cc/0x560 net/ipv4/tcp_output.c:1062 tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784 __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:create_zero_mask arch/x86/include/asm/word-at-a-time.h:61 [inline] RIP: 0010:strscpy+0xbb/0x2a0 lib/string.c:206 Code: 07 0f 86 a1 00 00 00 4a 8d 3c 2b e8 3f ff ff ff 48 89 c6 48 f7 d0 4a 8d 3c 36 48 21 f8 4b 8d 3c 2f 48 21 e8 74 a7 48 8d 48 ff <48> f7 d0 49 89 f8 48 21 c8 49 c1 e8 03 48 b9 00 00 00 00 00 fc ff RSP: 0018:ffffc9000f956f10 EFLAGS: 00000286 RAX: 8080000000000000 RBX: ffff88801b128830 RCX: 807fffffffffffff RDX: ffffed1003625108 RSI: 0000322e726f7475 RDI: ffff88801313c830 RBP: 8080808080808080 R08: 0000000000000000 R09: ffff88801b128838 R10: ffffed1003625107 R11: 0000000000000001 R12: 0000000000000010 R13: 0000000000000008 R14: fefefefefefefeff R15: ffff88801313c828 strscpy include/linux/fortify-string.h:170 [inline] strscpy_pad+0x20/0x70 lib/string_helpers.c:788 __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 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 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3089 slab_alloc_node mm/slub.c:3180 [inline] kmem_cache_alloc_node+0x122/0x3f0 mm/slub.c:3264 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1337 [inline] __ip6_append_data.isra.0+0x2e3c/0x3df0 net/ipv6/ip6_output.c:1642 ip6_append_data+0x1e7/0x550 net/ipv6/ip6_output.c:1811 rawv6_sendmsg+0x14ff/0x3ab0 net/ipv6/raw.c:949 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x32b/0x800 net/socket.c:2445 ___sys_sendmsg+0xf3/0x170 net/socket.c:2499 __sys_sendmmsg+0x195/0x470 net/socket.c:2585 __do_sys_sendmmsg net/socket.c:2614 [inline] __se_sys_sendmmsg net/socket.c:2611 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2611 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: 0033:0x7ff6754890e9 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:00007ff6766aa168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007ff67559bf60 RCX: 00007ff6754890e9 RDX: 00000000000002e9 RSI: 0000000020000480 RDI: 0000000000000003 RBP: 00007ff6754e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffed70d05f R14: 00007ff6766aa300 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