------------[ cut here ]------------ refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 1 PID: 32024 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Modules linked in: CPU: 1 PID: 32024 Comm: syz-executor.5 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Code: 1d 6a 5a e8 09 31 ff 89 de e8 8d 1a ab fd 84 db 75 e0 e8 d4 13 ab fd 48 c7 c7 a0 e1 c1 89 c6 05 4a 5a e8 09 01 e8 2e 36 fb 04 <0f> 0b eb c4 e8 b8 13 ab fd 0f b6 1d 39 5a e8 09 31 ff 89 de e8 58 RSP: 0018:ffffc9001a2a7990 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815c51f5 RDI: fffff52003454f24 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815bdf8e R11: 0000000000000000 R12: dffffc0000000000 R13: ffffc9001a2a7ad8 R14: ffff888093ec8568 R15: ffff88814bf6ee80 FS: 00007f2f88b1e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000540198 CR3: 0000000076422000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] dev_put include/linux/netdevice.h:4135 [inline] unregister_netdevice_many+0x121e/0x1780 net/core/dev.c:11037 unregister_netdevice_queue+0x2dd/0x3c0 net/core/dev.c:10934 register_netdevice+0x10d6/0x1500 net/core/dev.c:10292 register_netdev+0x2d/0x50 net/core/dev.c:10380 sit_init_net+0x3a4/0xb20 net/ipv6/sit.c:1917 ops_init+0xaf/0x470 net/core/net_namespace.c:140 setup_net+0x40f/0xa30 net/core/net_namespace.c:333 copy_net_ns+0x31e/0x760 net/core/net_namespace.c:474 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x8e0 kernel/fork.c:2998 __do_sys_unshare kernel/fork.c:3066 [inline] __se_sys_unshare kernel/fork.c:3064 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3064 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2f88b1e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffe359e6b3f R14: 00007f2f88b1e300 R15: 0000000000022000