* m0rtal f!w <mortalfw@gmail.com> [2018-07-12 19:55:56 +0530]:
> Team,
>
> File: stdlib.h#L:113
>
> i.e
> char *realpath (const char *__restrict, char *__restrict);
>
> According to the documentation of realpath() the output buffer needs to be
> at least of size PATH_MAX specifying output buffers large enough to handle
> the maximum-size possible result from path manipulation functions. (In that
> instance, buf's size comes from uv__fs_pathmax_size(). That function
> attempts to use pathconf(path, _PC_PATH_MAX) as noted in the realpath(3)
> docs)
>

sounds like a portability bug in uv__fs_pathmax_size()

http://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html

it should use PATH_MAX if defined or null pointer if not
to be portable to posix conforming targets.

> But over here uv__fs_pathmax_size() nor pathconf(path, _PC_PATH_MAX) is
> used.
>

where?

> Passing an inadequately-sized output buffer to a path manipulation function
> can result in a buffer overflow. Such functions include realpath()
> readlink() PathAppend() and others.
>
> Request team to have a look and validate.
>
>
> Thank you