libnv: verify that string is null terminated

During unpacking, we ensure that we do not read beyond the
declared size. However, unpack uses a function that copies
null-terminated strings. Prior to this commit, if the last string
was not null-terminated, it could result in copying data into a
buffer smaller than the allocated size.

Security:       FreeBSD-24:09.libnv
Security:       CVE-2024-45288
Security:       CAP-03
Reported by:    Synacktiv
Sponsored by:   The Alpha-Omega Project
Sponsored by:   The FreeBSD Foundation
Differential Revision:  https://reviews.freebsd.org/D46138

(cherry picked from commit 3aaaca1b51ad844ef9e9b3d945217ab3dd189bae)
(cherry picked from commit 03bef9971d73621e1703a0bad41b598bc2fce9c6)

Approved by:	so

0 files changed, 0 insertions, 0 deletions