rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15132/1:b..l rcu: (detected by 0, t=10503 jiffies, g=71681, q=2277 ncpus=2) task:syz.3.2002 state:R running task stack:23872 pid:15132 tgid:15121 ppid:12297 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5314 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6697 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7020 irqentry_exit+0x6f/0x90 kernel/entry/common.c:196 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x58/0x360 kernel/locking/lockdep.c:5834 Code: 8b 05 9c fc 07 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 9f fc 07 11 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 88 17 06 0e <73> 16 e8 31 f7 08 00 84 c0 75 0d f6 05 b2 f7 ef 0d 01 0f 84 d7 01 RSP: 0018:ffffc9000de3e9f8 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13c5a0 RBP: ffffffff81729ea5 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000de3ebb8 R11: ffffffff81ac7b20 R12: 0000000000000002 R13: ffffffff8e13c5a0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 discard_slab mm/slub.c:2753 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3218 put_cpu_partial+0x17c/0x250 mm/slub.c:3293 __slab_free+0x2d5/0x3c0 mm/slub.c:4550 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4281 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:578 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:669 alloc_skb include/linux/skbuff.h:1336 [inline] alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6665 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2974 sock_alloc_send_skb include/net/sock.h:1847 [inline] __ip6_append_data+0x2b43/0x3f30 net/ipv6/ip6_output.c:1664 ip6_append_data+0x1c4/0x380 net/ipv6/ip6_output.c:1859 l2tp_ip6_sendmsg+0x1286/0x17c0 net/l2tp/l2tp_ip6.c:654 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x19c/0x270 net/socket.c:729 ____sys_sendmsg+0x52d/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmmsg+0x227/0x430 net/socket.c:2757 __do_sys_sendmmsg net/socket.c:2784 [inline] __se_sys_sendmmsg net/socket.c:2781 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2781 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: 0033:0x7f1c2078e929 RSP: 002b:00007f1c2151d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f1c209b6160 RCX: 00007f1c2078e929 RDX: 17fd147c801ae9ab RSI: 0000200000000ac0 RDI: 000000000000000a RBP: 00007f1c20810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1c209b6160 R15: 00007ffe1d2641d8