An issue was discovered in fs/xfs/libxfs/xfs_attr_leaf.c in the Linux kernel through 4.17.3. An OOPS may occur for a corrupted xfs image after xfs_da_shrink_inode() is called with a NULL bp.
https://usn.ubuntu.com/3754-1/
https://usn.ubuntu.com/3753-2/
https://usn.ubuntu.com/3753-1/
https://usn.ubuntu.com/3752-3/
https://usn.ubuntu.com/3752-2/
https://usn.ubuntu.com/3752-1/
https://lists.debian.org/debian-lts-announce/2020/03/msg00001.html
https://github.com/torvalds/linux/commit/bb3d48dcf86a97dc25fe9fc2c11938e19cb4399a
https://bugzilla.kernel.org/show_bug.cgi?id=199969
https://access.redhat.com/errata/RHSA-2019:2043