------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 9207 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline] WARNING: CPU: 0 PID: 9207 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 lib/refcount.c:154 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9207 Comm: syz-executor381 Not tainted 5.1.0-rc5+ #74 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/0x65c kernel/panic.c:214 __warn.cold+0x20/0x45 kernel/panic.c:571 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:973 RIP: 0010:refcount_inc_checked lib/refcount.c:156 [inline] RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:154 Code: 1d b7 47 2a 06 31 ff 89 de e8 3b 50 40 fe 84 db 75 dd e8 f2 4e 40 fe 48 c7 c7 20 78 a1 87 c6 05 97 47 2a 06 01 e8 dd fc 12 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:ffff888086c2f8b8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815afcb6 RDI: ffffed1010d85f09 RBP: ffff888086c2f8c8 R08: ffff888086d38100 R09: ffff888086d389a0 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880947b07b8 R13: 0000000000000000 R14: ffff8880a0086ac0 R15: ffff88808ada4998 kref_get include/linux/kref.h:47 [inline] kobject_get+0x66/0xc0 lib/kobject.c:613 cdev_get+0x60/0xb0 fs/char_dev.c:358 chrdev_open+0xb0/0x6b0 fs/char_dev.c:403 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+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x407391 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 8a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 d3 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fa5642a6960 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000407391 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fa5642a6970 RBP: 6666666666666667 R08: 000000000000000f R09: 00007fa5642a7700 R10: 00007fa5642a79d0 R11: 0000000000000293 R12: 00000000006e4a1c R13: 0000000000000000 R14: 0000000000000000 R15: 00000000317a7973 Kernel Offset: disabled Rebooting in 86400 seconds..