Alexey IzbyshevandRich Felker
595416b11d
If the buffer passed to getservbyport_r is just enough to store two pointers after aligning it, getnameinfo is called with buflen == 0 (which means that service name is not needed) and trivially succeeds. Then, strtol is called on the address just past the buffer end, and if it doesn't happen to find the port number there, getservbyport_r spuriously succeeds and returns the same bad address to the caller. Fix this by ensuring that buflen is at least 1 when passed to getnameinfo.
musl libc
musl, pronounced like the word "mussel", is an MIT-licensed
implementation of the standard C library targetting the Linux syscall
API, suitable for use in a wide range of deployment environments. musl
offers efficient static and dynamic linking support, lightweight code
and low runtime overhead, strong fail-safe guarantees under correct
usage, and correctness in the sense of standards conformance and
safety. musl is built on the principle that these goals are best
achieved through simple code that is easy to understand and maintain.
The 1.1 release series for musl features coverage for all interfaces
defined in ISO C99 and POSIX 2008 base, along with a number of
non-standardized interfaces for compatibility with Linux, BSD, and
glibc functionality.
For basic installation instructions, see the included INSTALL file.
Information on full musl-targeted compiler toolchains, system
bootstrapping, and Linux distributions built on musl can be found on
the project website:
http://www.musl-libc.org/