New subject: [TUHS] buffer overflow (Re: Happy birthday Morris worm

13 Nov 2019

(Narrowly diverted in time to COFF from TUHS when I saw Warren's email, so 
I hope Warner is on it.)

On Tue, 12 Nov 2019, Warner Losh wrote:

...
  POSIX can't even recognize that leap seconds
exist :( 
There's a movement afoot to abolish leap seconds because they are 
"inconvenient" or something; that will upset the astronomers and other 
people who care about the exact time.

...
        All is not lost, though; use strncpy() instead
of strcpy() etc. 

 strncpy has two issues. First, it doesn't guarantee NUL termination. 
 Second, it always writes N bytes. It's for a fixed width data field, not 
 a variable length string whose buffer size is known. strlcpy is much 
 better, but still has some issues... 
Yeah, I knew about the NUL termination (or lack of it) - I didn't think to 
mention it.  When I use it, I copy n-1 bytes and plant the NUL in there 
myself (depending on how I'm using it).

And I wasn't aware of strlcpy() - thanks.  Too many functions to keep 
track of these days....

Trivia: curious to see how Australia's "talking clock" (long gone in 
favour of NTP, alas) handled the leap second, I recorded it (it puts a gap 
before the last beep).  It can be heard (and seen!) over on 
www.horsfall.org/leapsecond.webm .

And yes, that old long-haired hippie is me...

-- Dave

Re: [COFF] [TUHS] buffer overflow (Re: Happy birthday Morris worm