rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11176/1:b..l rcu: (detected by 0, t=10503 jiffies, g=48585, q=377 ncpus=2) task:syz.1.1489 state:R running task stack:27440 pid:11176 tgid:11163 ppid:5820 task_flags:0x400040 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5367 [inline] __schedule+0x1ac3/0x5090 kernel/sched/core.c:6748 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7070 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_stack_info_noinstr+0xf/0x130 arch/x86/kernel/dumpstack_64.c:172 Code: 29 07 00 eb 9a 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 41 56 41 54 53 49 89 d4 <48> 89 f3 48 89 fd e8 26 01 00 00 41 b6 01 84 c0 0f 85 cf 00 00 00 RSP: 0018:ffffc9000c05f1b8 EFLAGS: 00000282 RAX: 1ffff9200180be57 RBX: ffffc9000c05f280 RCX: ffffc9000c05f2a0 RDX: ffffc9000c05f280 RSI: ffff88802e2e0000 RDI: ffffc9000c05f220 RBP: ffff88802e2e0000 R08: ffffc9000c05f2df R09: 0000000000000000 R10: ffffc9000c05f280 R11: fffff5200180be5c R12: ffffc9000c05f280 R13: ffffc9000c05f2a8 R14: ffffc9000c05f2a0 R15: 1ffff9200180be55 get_stack_info+0x3c/0xf0 arch/x86/kernel/dumpstack_64.c:199 __unwind_start+0x434/0x740 arch/x86/kernel/unwind_orc.c:729 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe7/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x79/0x440 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2707 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3176 put_cpu_partial+0x17e/0x250 mm/slub.c:3251 __slab_free+0x294/0x390 mm/slub.c:4503 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4138 [inline] slab_alloc_node mm/slub.c:4187 [inline] kmem_cache_alloc_node_noprof+0x1f2/0x3b0 mm/slub.c:4239 kmalloc_reserve+0xa8/0x2a0 net/core/skbuff.c:515 __alloc_skb+0x1f2/0x480 net/core/skbuff.c:606 netlink_sendmsg+0x65c/0xce0 net/netlink/af_netlink.c:1857 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53c/0x870 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x271/0x360 net/socket.c:2659 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8b1f8d169 RSP: 002b:00007ff8b2e3b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff8b21a6160 RCX: 00007ff8b1f8d169 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000005 RBP: 00007ff8b200e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007ff8b21a6160 R15: 00007ffedb83fc38 rcu: rcu_preempt kthread starved for 6711 jiffies! g48585 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:26704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5367 [inline] __schedule+0x1ac3/0x5090 kernel/sched/core.c:6748 __schedule_loop kernel/sched/core.c:6825 [inline] schedule+0x163/0x360 kernel/sched/core.c:6840 schedule_timeout+0x15b/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111