An issue was discovered in the Linux kernel through 4.17.10. There is an invalid pointer dereference in io_ctl_map_page() when mounting and operating a crafted btrfs image, because of a lack of block group item validation in check_leaf_item in fs/btrfs/tree-checker.c.
https://patchwork.kernel.org/patch/10503147/
https://bugzilla.kernel.org/show_bug.cgi?id=199849
http://www.securityfocus.com/bid/104917
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://usn.ubuntu.com/3932-2/
https://usn.ubuntu.com/3932-1/
https://usn.ubuntu.com/4094-1/
https://usn.ubuntu.com/4118-1/
https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html
https://lists.debian.org/debian-lts-announce/2020/06/msg00013.html
Source: MITRE
Published: 2018-07-27
Updated: 2021-06-14
Type: CWE-476
Base Score: 7.1
Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C
Impact Score: 6.9
Exploitability Score: 8.6
Severity: HIGH
Base Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Impact Score: 3.6
Exploitability Score: 1.8
Severity: MEDIUM