Re: libpam-heimdal

[Assar Westerlund <assar@sics.se>]

Brian May <bam@snoopy.apana.org.au> writes:
> Hello,

Hi.

> I can't get this to work anymore with Heimdal 0.3f. With debug
> enabled, I get messages like:

this being the PAM module that's generally known as `pam_krb' ?

> Jun 19 20:28:55 scrooge login[28733]: pam_krb5: pam_sm_authenticate(login bam): entry: 
> Jun 19 20:29:01 scrooge login[11751]: pam_krb5: pam_sm_authenticate(login bam): entry: 
> Jun 19 20:29:55 scrooge login[2014]: pam_krb5: pam_sm_authenticate(login bam): entry: 

That's not very useful.

> I adopted the patch file I had for Heimdal 0.3e, attached (is this
> still required?), but it still doesn't work :-(

What is that patch supposed to do?

> Program received signal SIGSEGV, Segmentation fault.
> 0x400cc2ab in malloc () from /lib/libc.so.6
> (gdb) bt
> #0  0x400cc2ab in malloc () from /lib/libc.so.6
> #1  0x400cb964 in malloc () from /lib/libc.so.6
> #2  0x400c5712 in vasprintf () from /lib/libc.so.6
> #3  0x401c85dd in krb5_vset_error_string () from /usr/lib/libkrb5.so.16
> #4  0x401c85a1 in krb5_set_error_string () from /usr/lib/libkrb5.so.16
> #5  0x401cef2e in krb5_kt_remove_entry () from /usr/lib/libkrb5.so.16
> #6  0x401ceb46 in krb5_kt_start_seq_get () from /usr/lib/libkrb5.so.16
> #7  0x401ce8d8 in krb5_kt_get_entry () from /usr/lib/libkrb5.so.16
> #8  0x401ce775 in krb5_kt_read_service_key () from /usr/lib/libkrb5.so.16
> #9  0x40190936 in verify_krb_v5_tgt () from /lib/security/pam_krb5.so
> #10 0x4018f23e in pam_sm_authenticate () from /lib/security/pam_krb5.so
> #11 0x4004e926 in pam_fail_delay () from /lib/libpam.so.0
> #12 0x4004ebd4 in _pam_dispatch () from /lib/libpam.so.0
> #13 0x400504be in pam_authenticate () from /lib/libpam.so.0
> #14 0x804ad3e in strcpy ()
> #15 0x4007838b in __libc_start_main () from /lib/libc.so.6
> 
> Any ideas?

This does look like memory corruption (since it's getting a segv in
malloc).  Debugging that can be hairy, but electricfence or something
like that should help.

/assar