------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 8619 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline]
WARNING: CPU: 1 PID: 8619 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 lib/refcount.c:154
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8619 Comm: syz-executor600 Not tainted 5.1.0-rc5-next-20190418 #28
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/0x72b kernel/panic.c:214
 __warn.cold+0x20/0x46 kernel/panic.c:576
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972
RIP: 0010:refcount_inc_checked lib/refcount.c:156 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:154
Code: 1d e2 48 28 06 31 ff 89 de e8 eb 00 3d fe 84 db 75 dd e8 a2 ff 3c fe 48 c7 c7 00 1e a2 87 c6 05 c2 48 28 06 01 e8 ed 79 0f fe <0f> 0b eb c1 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41
RSP: 0018:ffff8880a45cf8b8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815b2ba6 RDI: ffffed10148b9f09
RBP: ffff8880a45cf8c8 R08: ffff88809a684580 R09: ffff88809a684e20
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880909478b8
R13: 0000000000000000 R14: ffff88809ed43a80 R15: ffff88809488ced0
 kref_get include/linux/kref.h:47 [inline]
 kobject_get+0x66/0xc0 lib/kobject.c:613
 cdev_get+0x60/0xb0 fs/char_dev.c:354
 chrdev_open+0xb0/0x6b0 fs/char_dev.c:399
 do_dentry_open+0x4e2/0x1250 fs/open.c:777
 vfs_open+0xa0/0xd0 fs/open.c:886
 do_last fs/namei.c:3416 [inline]
 path_openat+0x10e9/0x46e0 fs/namei.c:3533
 do_filp_open+0x1a1/0x280 fs/namei.c:3563
 do_sys_open+0x3fe/0x5d0 fs/open.c:1069
 __do_sys_open fs/open.c:1087 [inline]
 __se_sys_open fs/open.c:1082 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1082
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x405811
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a4 18 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fc3ae316960 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fc3ae316970
RBP: 6666666666666667 R08: 000000000000000f R09: 00007fc3ae317700
R10: 00007fc3ae3179d0 R11: 0000000000000293 R12: 00000000006dbc3c
R13: 0000000000000000 R14: 0000000000000000 R15: 00000000317a7973
Kernel Offset: disabled
Rebooting in 86400 seconds..