general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 25 Comm: kworker/u4:1 Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:dst_dev_put+0x1f/0x2a0 net/core/dst.c:156 Code: 1f 84 00 00 00 00 00 0f 1f 40 00 41 55 41 54 55 53 48 89 fb e8 22 69 71 fa 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 61 02 00 00 48 8d 7b 3a 4c 8b 23 48 b8 00 00 00 RSP: 0018:ffffc90000007d78 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000100 RDX: 0000000000000000 RSI: ffffffff87028d3e RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888025bec56b R10: ffffffff8792b8e5 R11: 0000000000084087 R12: 0000000000000007 R13: fffffbfff1b8c2bc R14: 0000607f46042558 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67e216e000 CR3: 00000000260ad000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: rt_fibinfo_free_cpus.part.0+0xda/0x140 net/ipv4/fib_semantics.c:202 rt_fibinfo_free_cpus net/ipv4/fib_semantics.c:194 [inline] fib_nh_common_release+0x10c/0x350 net/ipv4/fib_semantics.c:215 fib_nh_release net/ipv4/fib_semantics.c:227 [inline] free_fib_info_rcu+0x24b/0x4d0 net/ipv4/fib_semantics.c:239 rcu_do_batch kernel/rcu/tree.c:2559 [inline] rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:205 Code: 1d 8d d3 bc 7e 65 8b 05 86 d3 bc 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 a5 0d 09 00 e8 20 c9 34 00 fb 65 8b 05 68 d3 bc 7e <85> c0 74 58 5b 5d c3 65 8b 05 96 da bc 7e 85 c0 75 a2 0f 0b eb 9e RSP: 0018:ffffc90000dff780 EFLAGS: 00000206 RAX: 0000000080000000 RBX: 00000000fffffe01 RCX: 1ffffffff1f5de1a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff87417063 R08: 0000000000000001 R09: ffffffff8fae28c7 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8bc70dc0 R13: 0000000000003b0d R14: 0000000000000000 R15: 0000000000000001 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2237 [inline] nf_ct_iterate_cleanup+0x15a/0x450 net/netfilter/nf_conntrack_core.c:2260 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2348 [inline] nf_ct_iterate_cleanup_net+0x290/0x3f0 net/netfilter/nf_conntrack_core.c:2332 masq_device_event+0xae/0xe0 net/netfilter/nf_nat_masquerade.c:88 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2121 call_netdevice_notifiers_extack net/core/dev.c:2133 [inline] call_netdevice_notifiers net/core/dev.c:2147 [inline] dev_close_many+0x2ff/0x620 net/core/dev.c:1722 unregister_netdevice_many+0x3fd/0x1780 net/core/dev.c:10983 default_device_exit_batch+0x2fa/0x3c0 net/core/dev.c:11536 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:178 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: ---[ end trace 886a0894c5707c16 ]--- RIP: 0010:dst_dev_put+0x1f/0x2a0 net/core/dst.c:156 Code: 1f 84 00 00 00 00 00 0f 1f 40 00 41 55 41 54 55 53 48 89 fb e8 22 69 71 fa 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 61 02 00 00 48 8d 7b 3a 4c 8b 23 48 b8 00 00 00 RSP: 0018:ffffc90000007d78 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000100 RDX: 0000000000000000 RSI: ffffffff87028d3e RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888025bec56b R10: ffffffff8792b8e5 R11: 0000000000084087 R12: 0000000000000007 R13: fffffbfff1b8c2bc R14: 0000607f46042558 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67e216e000 CR3: 00000000260ad000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600