input: syz1 as /devices/virtual/input/input1408 input: syz1 as /devices/virtual/input/input1409 input: syz1 as /devices/virtual/input/input1410 refcount_t: increment on 0; use-after-free. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 13467 at lib/refcount.c:153 refcount_inc lib/refcount.c:153 [inline] WARNING: CPU: 1 PID: 13467 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: 13467 Comm: syz-executor121 Not tainted 4.14.113 #3 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+0x138/0x19c lib/dump_stack.c:53 panic+0x1f2/0x438 kernel/panic.c:182 __warn.cold+0x2f/0x34 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:944 RIP: 0010:refcount_inc lib/refcount.c:153 [inline] RIP: 0010:refcount_inc.cold+0x18/0x1f lib/refcount.c:151 RSP: 0018:ffff888092adf980 EFLAGS: 00010286 RAX: 000000000000002b RBX: 1ffff1101255bf3d RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff88807cf7eec0 RDI: ffffed101255bf26 RBP: ffff888092adf988 R08: 000000000000002b R09: ffff88807cf7eee0 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807312efe0 R13: 0000000000000000 R14: ffff88809359a080 R15: ffff888097308ee8 kref_get include/linux/kref.h:47 [inline] kobject_get+0x5b/0x70 lib/kobject.c:596 cdev_get+0x54/0xa0 fs/char_dev.c:358 chrdev_open+0x9b/0x590 fs/char_dev.c:403 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 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:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x405811 RSP: 002b:00007fdcf8140960 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405811 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fdcf8140970 RBP: 6666666666666667 R08: 000000000000000f R09: 00007fdcf8141700 R10: 00007fdcf81419d0 R11: 0000000000000293 R12: 00000000006dbc3c R13: 0000000000000000 R14: 0000000000000000 R15: 00000000317a7973 Kernel Offset: disabled Rebooting in 86400 seconds..