Strange segmentation fault in libkrb5.so.3.3 (1.6.4-beta1)

[Dan Searle]

Hi,

If memory clobbering is causing an invalid call to free() then why is 
the top of the stack trace showing to calls within ld-linux? and why is 
there no call to free()? There are enough debug symbols in libc for 
that. Also it's not proacicle to run the application in valgrind because 
this error only happens once every couple of days or so in a production 
environment and the applicationw would run too slowly to be useful and 
also the memory requirements would be too large.

Russ Allbery wrote:
> Dan Searle <dan.searle at censornet.com> writes:
>
>   
>> We have an application which uses pam_krb5.so to perform user auth,
>> however sometimes it SEGV's in ld-linux, but ld-linux is invoked from
>> within libkrb5.so.3.3, see this trace and gdb diagnostics:
>>     
>
> Which pam_krb5 and what version?
>
> You forgot to star out another copy of the password, btw, so you will want
> to change that password.
>
>   
>>    if (chpw_opts)
>>       krb5_get_init_creds_opt_free(context, chpw_opts);
>>  ^^^^^^^^^^^^^^^^^^^ Line 398 above ^^^^^^^^^^^^^^^^^^^^^^
>>     
>
> I suspect a memory clobber and that you're getting a segfault in free()
> that gdb isn't figuring out because you don't have enough debugging
> symbols.  Try running your application under valgrind and see if that
> turns it up.
>
>   
> ------------------------------------------------------------------------
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com 
> Version: 9.0.730 / Virus Database: 270.14.150/2632 - Release Date: 01/19/10 07:34:00
>
>   


------------------------------------------------------------------------------------
Scanned for viruses, spam and offensive content by CensorNet MailSafe

Try CensorNet free for 14 days. Provide Internet access on your terms.
Visit www.censornet.com for more information.