------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 0 PID: 19913 at lib/refcount.c:156 refcount_inc_checked+0x4b/0x50 lib/refcount.c:156
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 19913 Comm: syz-executor.0 Not tainted 5.2.0-rc5+ #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+0x1d8/0x2f8 lib/dump_stack.c:113
 panic+0x28a/0x7c9 kernel/panic.c:219
 __warn+0x216/0x220 kernel/panic.c:576
 report_bug+0x190/0x290 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap+0xd7/0x450 arch/x86/kernel/traps.c:272
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:refcount_inc_checked+0x4b/0x50 lib/refcount.c:156
Code: 3d 97 72 7a 05 01 75 08 e8 42 52 16 fe 5b 5d c3 e8 3a 52 16 fe c6 05 81 72 7a 05 01 48 c7 c7 01 4c 66 88 31 c0 e8 25 24 e8 fd <0f> 0b eb df 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0
RSP: 0018:ffff8880821576d8 EFLAGS: 00010246
RAX: a72e72be004b6e00 RBX: ffff8880506858f8 RCX: 0000000000040000
RDX: ffffc90005de1000 RSI: 000000000000baa6 RDI: 000000000000baa7
RBP: ffff8880821576e0 R08: ffffffff815e87e4 R09: fffffbfff115a505
R10: fffffbfff115a505 R11: 1ffffffff115a504 R12: dffffc0000000000
R13: ffff8880506858c0 R14: ffff8880506858fc R15: ffff8880506858c0
 kref_get include/linux/kref.h:45 [inline]
 kobject_get+0x91/0xc0 lib/kobject.c:642
 cdev_get fs/char_dev.c:354 [inline]
 chrdev_open+0x1d1/0x670 fs/char_dev.c:399
 do_dentry_open+0x7ba/0x1060 fs/open.c:778
 vfs_open+0x73/0x80 fs/open.c:887
 do_last fs/namei.c:3416 [inline]
 path_openat+0x136d/0x4400 fs/namei.c:3533
 do_filp_open+0x1f7/0x430 fs/namei.c:3563
 do_sys_open+0x343/0x620 fs/open.c:1070
 __do_sys_open fs/open.c:1088 [inline]
 __se_sys_open fs/open.c:1083 [inline]
 __x64_sys_open+0x87/0x90 fs/open.c:1083
 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4131b1
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f6e6f2b87a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 00000000004131b1
RDX: 0000000000000000 RSI: 0010000000000000 RDI: 00007f6e6f2b8850
RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000293 R12: 00007f6e6f2b96d4
R13: 00000000004c8455 R14: 00000000004decf0 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..