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.
www.securityfocus.com/bid/104917
bugzilla.kernel.org/show_bug.cgi?id=199837
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/10503415/
usn.ubuntu.com/3932-1/
usn.ubuntu.com/3932-2/
usn.ubuntu.com/4094-1/
usn.ubuntu.com/4118-1/