An issue was discovered in the Linux kernel through 4.17.10. There is an invalid pointer dereference in btrfs_root_node() when mounting a crafted btrfs image, because of a lack of chunk block group mapping validation in btrfs_read_block_groups in fs/btrfs/extent-tree.c, and a lack of empty-tree checks in check_leaf in fs/btrfs/tree-checker.c.
www.securityfocus.com/bid/104917
bugzilla.kernel.org/show_bug.cgi?id=199847
lists.debian.org/debian-lts-announce/2019/03/msg00017.html
lists.debian.org/debian-lts-announce/2020/06/msg00011.html
lists.debian.org/debian-lts-announce/2020/06/msg00013.html
patchwork.kernel.org/patch/10503403/
patchwork.kernel.org/patch/10503413/
usn.ubuntu.com/3932-1/
usn.ubuntu.com/3932-2/
usn.ubuntu.com/4094-1/
usn.ubuntu.com/4118-1/