[ic] vlink MINIVEND_SOCKET patch

[Peter]

On 6/05/20 4:58 am, Jon Jensen wrote:
> On Tue, 5 May 2020, David Christensen wrote:
> 
>>> +  strncpy(sa.sun_path, lsocket, sizeof(sa.sun_path) - 1);
>>
>> A couple of questions: is the sa struct guaranteed to be zero’d, so we 
>> don’t need to worry about a NULL terminator (i.e., why there’s a -1 in 
>> sizeof call)?
> 
> Using 1 byte smaller than sizeof, strncpy() guarantees null termination, 
> because it clears the rest of the buffer, so it will have at least one 
> null at the end.

Exactly, and I took the code almost verbatim from unix(7):
http://man7.org/linux/man-pages/man7/unix.7.html

>> Also, if strlen(lsocket) > sizeof(sa.sun_path), a truncated copy would 
>> end up being bunko, since it won’t refer to an actual valid path; 
>> would it be better to just check if strlen(lsocket) > 
>> sizeof(sa.sun_path) -1 and error out if so?
> 
> Great point. No reason to proceed if the filename will be truncated.

I agree, but I think we should do both, even though only one or the 
other is needed to prevent a buffer overflow both just makes doubly 
safe, and I tend to prefer to get rid of strcpy in favor of strncpy 
where I see it.

BTW I just stayed up nearly all night rewriting the spec file.  I think 
it will be nice to have some decent RPM packages to go along with the 
5.12.0 release which I'm happy to host in GhettoForge.  I'll be testing 
tomorrow.


Peter