Commit Graph

4 Commits

Author SHA1 Message Date
Jessica Clarke
63d24336fd Fix off-by-one error in msdosfs FAT32 volume label copying
I dropped the + 1 from the other two instances in each file but failed
to do so for this one, resulting in a more egregious buffer overread
than the one I was fixing (since the read character ended up in the
output if there was space).

Reported by:	Jenkins
Fixes:	34fb1c133c ("Fix intra-object buffer overread for labeled msdosfs volumes")
2021-10-28 01:01:00 +01:00
Jessica Clarke
34fb1c133c Fix intra-object buffer overread for labeled msdosfs volumes
Volume labels, like directory entries, are padded with spaces and so
have no NUL terminator. Whilst the MIN for the dsize argument to strlcpy
ensures that the copy does not overflow the destination, strlcpy is
defined to return the number of characters in the source string,
regardless of the provided dsize, and so keeps reading until it finds a
NUL, which likely exists somewhere within the following fields, but On
CHERI with the subobject bounds enabled in the compiler this buffer
overread will be detected and trap with a bounds violation.

Found by:	CHERI
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D32579
2021-10-27 18:38:37 +01:00
Edward Tomasz Napierala
628b712826 Fix off-by-one error in fstyp(8) and geom_label(4) that made them use
a single space (" ") as a CD9660 label name when no label was present.
Similar problem was also present in msdosfs label recognition.

PR:		200828
Differential Revision:	https://reviews.freebsd.org/D2830
Reviewed by:	asomers@, emaste@
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
2015-06-18 21:55:55 +00:00
Edward Tomasz Napierala
be3a49ee62 Add fstyp(8). This utility, named after its SVR4 counterpart, detects
filesystems.  It differs from file(1) in that it gives machine-parseable
output, it outputs filesystem labels, doesn't get confused by other
formats metadata, and runs in Capsicum sandbox.

Differential Revision:	https://reviews.freebsd.org/D1255
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
2014-12-10 14:14:16 +00:00