freebsd-dev/tools/diag
Jessica Clarke 5b13fa7987 ufs: Rework shortlink handling to avoid subobject overflows
Shortlinks occupy the space of both di_db and di_ib when used. However,
everywhere that wants to read or write a shortlink takes a pointer do
di_db and promptly runs off the end of it into di_ib. This is fine on
most architectures, if a little dodgy. However, on CHERI, the compiler
can optionally restrict the bounds on pointers to subobjects to just
that subobject, in order to mitigate intra-object buffer overflows, and
this is enabled in CheriBSD's pure-capability kernels.

Instead, clean this up by inserting a union such that a new di_shortlink
can be added with the right size and element type, avoiding the need to
cast and allowing the use of the DIP macro to access the field. This
also mirrors how the ext2fs code implements extents support, with the
exact same structure other than having a uint32_t i_data[] instead of a
char di_shortlink[].

Reviewed by:	mckusick, jhb
Differential Revision:	https://reviews.freebsd.org/D33650
2022-01-02 20:55:36 +00:00
..
dumpvfscache
localeck
prtblknos ufs: Rework shortlink handling to avoid subobject overflows 2022-01-02 20:55:36 +00:00
README

$FreeBSD$

This directory is for diagnostic programs.

A diagnostic program is one that will inform you that something is wrong
somewhere, for instance by traversing a kernel-structure and verifying
the integrity.

Please make a subdir per program, and add a brief description to this file.

dumpvfscache	program that can be used to examine the contents of the vfs
		name cache.
localeck	check for invalid/incomplete locales 
prtblknos	Print out the blocks used by each inode in the list