An issue was discovered in the Linux kernel through 4.17.10. There is an invalid pointer dereference in __del_reloc_root() in fs/btrfs/relocation.c when mounting a crafted btrfs image, related to removing reloc rb_trees when reloc control has not been initialized. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-14609
