------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 1 PID: 12599 at lib/refcount.c:156 refcount_inc_checked+0x4b/0x50 lib/refcount.c:156 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 12599 Comm: syz-executor314 Not tainted 5.3.0-rc4+ #78 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+0x25c/0x799 kernel/panic.c:219 __warn+0x22f/0x230 kernel/panic.c:576 report_bug+0x190/0x290 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] do_error_trap+0xd7/0x440 arch/x86/kernel/traps.c:272 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:refcount_inc_checked+0x4b/0x50 lib/refcount.c:156 Code: 3d 2e 8b 68 05 01 75 08 e8 52 53 21 fe 5b 5d c3 e8 4a 53 21 fe c6 05 18 8b 68 05 01 48 c7 c7 34 4b 45 88 31 c0 e8 85 3a f4 fd <0f> 0b eb df 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 10 RSP: 0018:ffff88808cb579b0 EFLAGS: 00010246 RAX: cd29ce2624bf4d00 RBX: ffff8880934dcc00 RCX: ffff88809eec65c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff88808cb579b8 R08: ffffffff815cf524 R09: ffffed1015d640d2 R10: ffffed1015d640d2 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880934dcbc8 R14: ffff8880934dcc04 R15: ffff8880934dcbc8 kref_get include/linux/kref.h:45 [inline] kobject_get+0x91/0xc0 lib/kobject.c:644 cdev_get fs/char_dev.c:355 [inline] chrdev_open+0x17e/0x590 fs/char_dev.c:400 do_dentry_open+0x73b/0xf90 fs/open.c:797 vfs_open+0x73/0x80 fs/open.c:906 do_last fs/namei.c:3416 [inline] path_openat+0x1397/0x4460 fs/namei.c:3533 do_filp_open+0x192/0x3d0 fs/namei.c:3563 do_sys_open+0x29f/0x560 fs/open.c:1089 __do_sys_open fs/open.c:1107 [inline] __se_sys_open fs/open.c:1102 [inline] __x64_sys_open+0x87/0x90 fs/open.c:1102 do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x406311 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:00007fb29f268960 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000406311 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fb29f268970 RBP: 6666666666666667 R08: 000000000000000f R09: 00007fb29f269700 R10: 00007fb29f2699d0 R11: 0000000000000293 R12: 00000000006dbc3c R13: 0000000000000000 R14: 0000000000000000 R15: 00000000317a7973 Kernel Offset: disabled Rebooting in 86400 seconds..