svn commit: r328492 - head/contrib/opie/libopie

[Bruce Evans]

On Sat, 27 Jan 2018, Pedro Giffuni wrote:

> On 01/27/18 18:21, Bruce Evans wrote:
>> On Sat, 27 Jan 2018, Dimitry Andric wrote:
>> 
>>> On 27 Jan 2018, at 23:20, Ed Schouten <ed at nuxi.nl> wrote:

>* [... context lost to corruption of spaces which makes it unreadable]

>>>> 
>>>> Wait... This may access utmp.ut_host one byte past the end and no
>>>> longer guarantees that host is null-terminated, right?
>> 
>>> No, strncpy "copies at most len characters from src into dst".  However,
>> 
>> No, the change breaks the length so 1 byte past the end is accessed
>> in implementations where ut_host is not guaranteed to be NUL terminated
>> and the current instance of ut_host is not NUL terminated.
>> 
> The main change is in the sizeof(). Regularly you should use the size of 
> destination not the source, and apparently GCC8 decided there was something 
> to check there.

That is the main breakage.  Using the size of the destination is very wrong,
since that size is intentionally 1 larger than the size of the source, to
leave space for appending a NUL.

> ...
> Looking in detail, upstream (which appears to have disappeared) does have the 
> explicit NULL termination in our last import. For consistency and given that 
> we already have a strlcpy in that code, we should use strlcpy() there. Every 
> modern OS out there has strlcpy(3) and if not they can figure out what to do.

strlcpy() still seems to be intentionally left out of glibc.

Bruce