input: syz1 as /devices/virtual/input/input1428 refcount_t: increment on 0; use-after-free. ------------[ cut here ]------------ kobject: '(null)' (ffff88805aa17868): calling ktype release WARNING: CPU: 1 PID: 19702 at lib/refcount.c:153 refcount_inc lib/refcount.c:153 [inline] WARNING: CPU: 1 PID: 19702 at lib/refcount.c:153 refcount_inc.cold+0x18/0x1f lib/refcount.c:151 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 19702 Comm: syz-executor.2 Not tainted 4.14.146 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x197 lib/dump_stack.c:53 panic+0x1f2/0x426 kernel/panic.c:182 __warn.cold+0x2f/0x36 kernel/panic.c:546 report_bug+0x216/0x254 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:177 [inline] fixup_bug arch/x86/kernel/traps.c:172 [inline] do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963 RIP: 0010:refcount_inc lib/refcount.c:153 [inline] RIP: 0010:refcount_inc.cold+0x18/0x1f lib/refcount.c:151 RSP: 0018:ffff88808b367980 EFLAGS: 00010286 RAX: 000000000000002b RBX: 1ffff1101166cf3d RCX: 0000000000000000 RDX: 000000000000828d RSI: ffffffff814b2e55 RDI: ffffed101166cf26 RBP: ffff88808b367988 R08: 000000000000002b R09: ffff88802fcc6920 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88805aa178a0 R13: 0000000000000000 R14: ffff8880a7d032c0 R15: ffff8880a8d9b488 kref_get include/linux/kref.h:47 [inline] kobject_get+0x5b/0x70 lib/kobject.c:596 cdev_get+0x54/0xa0 fs/char_dev.c:364 chrdev_open+0x9b/0x590 fs/char_dev.c:409 do_dentry_open+0x73b/0xeb0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:891 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1084 SYSC_open fs/open.c:1102 [inline] SyS_open+0x2d/0x40 fs/open.c:1097 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x413911 RSP: 002b:00007f376a7c47a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000413911 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f376a7c4850 RBP: 000000000075bfc8 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f376a7c56d4 R13: 00000000004c8df0 R14: 00000000004dfef8 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..