------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 0 PID: 29695 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 0 PID: 29695 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 29695 Comm: syz-executor3 Not tainted 5.0.0-rc2+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x48 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Code: 1d ec 4c c8 06 31 ff 89 de e8 5b 3e f2 fd 84 db 75 dd e8 12 3d f2 fd 48 c7 c7 a0 95 81 88 c6 05 cc 4c c8 06 01 e8 bf 8b bb fd <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49
kobject: 'loop4' (00000000f52bea1d): kobject_uevent_env
RSP: 0018:ffff888042ed6ed8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000be33000
RDX: 000000000001148d RSI: ffffffff81685456 RDI: 0000000000000005
RBP: ffff888042ed6ee8 R08: ffff88808b714000 R09: ffff88808b714940
R10: ffff88808b714000 R11: 0000000000000000 R12: ffff888095b4a4cc
R13: 0000000100005dc4 R14: ffff888095b4a440 R15: ffff8880a019ca40
kobject: 'loop4' (00000000f52bea1d): fill_kobj_path: path = '/devices/virtual/block/loop4'
 igmp_start_timer+0xac/0xe0 net/ipv4/igmp.c:214
 igmp_mod_timer net/ipv4/igmp.c:252 [inline]
 igmp_heard_query net/ipv4/igmp.c:1038 [inline]
 igmp_rcv+0x198d/0x3060 net/ipv4/igmp.c:1073
 ip_protocol_deliver_rcu+0xb6/0xa20 net/ipv4/ip_input.c:208
 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ip_local_deliver+0x1f0/0x740 net/ipv4/ip_input.c:255
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0x1f4/0x2f0 net/ipv4/ip_input.c:414
 NF_HOOK include/linux/netfilter.h:289 [inline]
 NF_HOOK include/linux/netfilter.h:283 [inline]
 ip_rcv+0xed/0x620 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973
 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083
 netif_receive_skb_internal+0x11e/0x690 net/core/dev.c:5186
 napi_frags_finish net/core/dev.c:5753 [inline]
 napi_gro_frags+0xd07/0xfe0 net/core/dev.c:5827
 tun_get_user+0x2ec2/0x4150 drivers/net/tun.c:1975
kobject: 'loop2' (00000000791c5975): kobject_uevent_env
 tun_chr_write_iter+0xbd/0x160 drivers/net/tun.c:2020
 call_write_iter include/linux/fs.h:1862 [inline]
 do_iter_readv_writev+0x902/0xbc0 fs/read_write.c:680
 do_iter_write fs/read_write.c:956 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:937
kobject: 'loop2' (00000000791c5975): fill_kobj_path: path = '/devices/virtual/block/loop2'
 vfs_writev+0x1ee/0x370 fs/read_write.c:1001
 do_writev+0x11a/0x300 fs/read_write.c:1036
 __do_sys_writev fs/read_write.c:1109 [inline]
 __se_sys_writev fs/read_write.c:1106 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1106
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
kobject: 'loop5' (00000000859b0115): kobject_uevent_env
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457d81
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a4 b8 fb ff c3 48 83 ec 08 e8 1a 2d 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 63 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f26e8b17ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000002a RCX: 0000000000457d81
RDX: 0000000000000001 RSI: 00007f26e8b17bf0 RDI: 00000000000000f0
RBP: 0000000020000640 R08: 00000000000000f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f26e8b186d4
kobject: 'loop5' (00000000859b0115): fill_kobj_path: path = '/devices/virtual/block/loop5'
R13: 00000000004c6426 R14: 00000000004db660 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..