[tac_plus] Strange Crash

[heasley]

Sat, Apr 28, 2018 at 11:59:14AM -0600, Daniel Schmidt:
> Well, that's just weird.  Why does the latest libpam google authenticator
> crash when using pap?  Works just fine for login.  Old libpam google
> doesn't crash.  Not sure where the problem is.
> 
> ╭─dans at cwacs ~/google-authenticator-libpam  ‹master›
> ╰─$ *** Error in `tac_plus': double free or corruption (!prev):
> 0x0000000000b3c000 ***
> ======= Backtrace: =========
> /lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7fb0082a37e5]
> /lib/x86_64-linux-gnu/libc.so.6(+0x8037a)[0x7fb0082ac37a]
> /lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7fb0082b053c]
> tac_plus[0x408f6a]
> tac_plus[0x404234]
> tac_plus[0x4129d0]
> tac_plus[0x40312f]
> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7fb00824c830]
> tac_plus[0x4037a9]
> ======= Memory map: ========
> 00400000-0041b000 r-xp 00000000 fc:00 135832
> /usr/local/bin/tac_plus
> 0061a000-0061b000 r--p 0001a000 fc:00 135832
> /usr/local/bin/tac_plus
> 0061b000-0061c000 rw-p 0001b000 fc:00 135832
> /usr/local/bin/tac_plus
> 0061c000-0061f000 rw-p 00000000 00:00 0
> 00b39000-00b5a000 rw-p 00000000 00:00 0
> [heap]
> (and so on)
> 

looking at the code surrounding the calls to PAM, its not obvious, if
its even there.

perhaps you can build tacacs with symbols and collect a core to share?