------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 8683 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 8683 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8683 Comm: syz-executor.3 Not tainted 5.0.0-rc6+ #73
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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
kobject: 'loop1' (00000000be25916b): kobject_uevent_env
 __warn.cold+0x20/0x45 kernel/panic.c:571
kobject: 'loop1' (00000000be25916b): fill_kobj_path: path = '/devices/virtual/block/loop1'
 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
kobject: 'loop2' (00000000d8209110): kobject_uevent_env
 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 cc e6 2e 06 31 ff 89 de e8 8b f1 45 fe 84 db 75 dd e8 42 f0 45 fe 48 c7 c7 e0 25 a2 87 c6 05 ac e6 2e 06 01 e8 ad 3b 19 fe <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41
kobject: 'loop2' (00000000d8209110): fill_kobj_path: path = '/devices/virtual/block/loop2'
RSP: 0018:ffff88804c047230 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000d398 RSI: ffffffff815a9256 RDI: ffffed1009808e38
RBP: ffff88804c047240 R08: ffff88808903e580 R09: ffff88808903ee98
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888099a7744c
R13: ffff888099a77400 R14: 0000000000000000 R15: ffff888099a773c0
 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+0x18ed/0x29b0 net/ipv4/igmp.c:1073
 ip_protocol_deliver_rcu+0x60/0x8e0 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+0x1e9/0x520 net/ipv4/ip_input.c:255
kobject: 'loop0' (0000000015b986c8): kobject_uevent_env
 dst_input include/net/dst.h:450 [inline]
 ip_rcv_finish+0x1db/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+0xe8/0x3f0 net/ipv4/ip_input.c:524
kobject: 'loop0' (0000000015b986c8): fill_kobj_path: path = '/devices/virtual/block/loop0'
 __netif_receive_skb_one_core+0x115/0x1a0 net/core/dev.c:4973
kobject: 'loop4' (00000000c7f2d3cd): kobject_uevent_env
 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083
 netif_receive_skb_internal+0x117/0x660 net/core/dev.c:5186
kobject: 'loop4' (00000000c7f2d3cd): fill_kobj_path: path = '/devices/virtual/block/loop4'
 netif_receive_skb+0x6e/0x5a0 net/core/dev.c:5261
 tun_rx_batched.isra.0+0x4f7/0x840 drivers/net/tun.c:1562
 tun_get_user+0x2588/0x38d0 drivers/net/tun.c:1991
 tun_chr_write_iter+0xbd/0x160 drivers/net/tun.c:2019
 call_write_iter include/linux/fs.h:1863 [inline]
 do_iter_readv_writev+0x5e0/0x8e0 fs/read_write.c:680
 do_iter_write fs/read_write.c:956 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:937
 compat_writev+0x1f6/0x3a0 fs/read_write.c:1270
 do_compat_writev+0xf5/0x1f0 fs/read_write.c:1291
 __do_compat_sys_writev fs/read_write.c:1302 [inline]
 __se_compat_sys_writev fs/read_write.c:1298 [inline]
 __ia32_compat_sys_writev+0x74/0xb0 fs/read_write.c:1298
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f4b869
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d47054 EFLAGS: 00000292 ORIG_RAX: 0000000000000092
RAX: ffffffffffffffda RBX: 00000000000000f0 RCX: 00000000f5d470a4
RDX: 0000000000000001 RSI: 0000000020000240 RDI: 00000000ffffffff
RBP: 00000000f5d47168 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..