libpkgconf: path: supply buffer to realpath #208

Merged
grobian merged 1 commits from master into master 2021-01-08 23:44:41 +00:00

1 Commits (master)

Author SHA1 Message Date
Fabian Groffen 6136f9c9d6 libpkgconf: path: supply buffer to realpath
To avoid a crash on some platforms (like Darwin 9) provide a buffer to
realpath(3).

Darwin 9 (last PPC target) documents realpath needs to be given a buffer
to the resolved_path argument large enough to hold PATH_MAX bytes.
With NULL argument it crashes.  Solaris makes no mention of
resolved_path to be allowed NULL, yet recent versions accept it and
malloc(3) accordingly.

Because the documentation explicitly mentions PATH_MAX being the limit
to what realpath(3) would write in resolved_path, switching to a static
buffer here doesn't limit resolution compared to dynamically allocating
a buffer by realpath(3).

While this change requires a bit more space on the stack, it avoids a
malloc/free sequence, and allows successful operation on (older)
platforms that lack support for dynamically allocating a return buffer
in realpath(3).

Signed-off-by: Fabian Groffen <grobian@gentoo.org>
2021-01-08 10:56:41 +01:00