An issue was discovered in the Linux kernel through 4.17.10. There is out-of-bounds access in write_extent_buffer() when mounting and operating a crafted btrfs image, because of a lack of verification that each block group has a corresponding chunk at mount time, within btrfs_read_block_groups in fs/btrfs/extent-tree.c.
CWE-125 - Out-of-Bounds Read
Out-of-bounds read is a vulnerability that allows access to memory beyond the authorized accessible location. Such a vulnerability compromises the confidentiality of the trusted environment in the application and enables an attacker to launch further attacks by leveraging the exposed information.