FW: Segfault with "net ads password"

[James Willard]

Hi All,
 
I'm still having the issues I've described below. I've tried to give as
much detail as possible, and I'm hoping to help fix this segfault bug in
what will become Samba 3. I don't believe that this problem is isolated
to me and I do believe that it does affect every other user. Please help
me and allow me to help the Samba project.
 
Thanks,
 
James Willard
james at whispering.org
 

-----Original Message-----
From: samba-technical-admin at lists.samba.org
[mailto:samba-technical-admin at lists.samba.org] On Behalf Of James
Willard
Sent: Friday, November 01, 2002 6:04 PM
To: 'Esh, Andrew'; samba-technical at samba.org
Subject: RE: Segfault with "net ads password"


Andrew,
 
It seems like you're right about the null pointer. Given the code block
you mentioned, I rebuilt with --enable-krb5developer and ran gdb over it
again with a breakpoint at net_ads_password() and displaying ads,
ads->auth, and ads->auth.kdc_server. The following is the output from
gdb at the line just before line 885 where kerberos_set_password() is
called:
 
3: ads->auth = {realm = 0x0, password = 0x0, user_name = 0x0, kdc_server
= 0x0, flags = 0, time_offset = 0}
2: ads->auth.kdc_server = 0x0
1: ads = (ADS_STRUCT *) 0x81af8e0

And of course, the call itself... null values and all...
(usernames/passwords substituted)
 
(gdb) 
kerberos_set_password (kpasswd_server=0x0, auth_principal=0x815c560
Admin at DOMAIN.COM, 
    auth_password=0x815c57c "Adminpass", target_principal=0xbffffbe5
User at DOMAIN.COM, 
    new_password=0x81535a0 "User", time_offset=0) at
libads/krb5_setpw.c:470
470         return krb5_set_password(kpasswd_server, target_principal,
new_password, time_offset);

Ok, this officially goes beyond my abilities... who maintains the "net
ads" portion of Samba that could help me look into this further?
 
Thanks,
 
James Willard
james at whispering.org
 

-----Original Message-----
From: Esh, Andrew [mailto:AEsh at tricord.com] 
Sent: Friday, November 01, 2002 4:54 PM
To: 'James Willard'; samba-technical at samba.org
Subject: RE: Segfault with "net ads password"
Importance: High



Looks like this bit of code is failing: 

utils/net_ads.c, lines 877-886, function "net_ads_password" 

    /* use the realm so we can eventually change passwords for users 
    in realms other than default */ 
    if (!(ads = ads_init(realm, NULL, NULL))) return -1; 

    asprintf(&prompt, "Enter new password for %s:", argv[0]); 

    new_password = getpass(prompt); 

    ret = kerberos_set_password(ads->auth.kdc_server, auth_principal, 
                                auth_password, argv[0], new_password,
ads->auth.time_offset); 

the last line is reached with "ads->auth.kdc_server" as a bad (null?)
pointer.  The "ads_init" function creates the ads structure and zeroes
it. It doesn't appear to me as though "ads_init" initializes ads->auth,
and I don't see where else it gets set.

-----Original Message----- 
From: James Willard [mailto:james at whispering.org] 
Sent: Friday, November 01, 2002 2:23 PM 
To: samba-technical at samba.org 
Subject: RE: Segfault with "net ads password" 


And as a follow-up to myself... The following is a backtrace from gdb: 

Program received signal SIGSEGV, Segmentation fault. 
0x080ec329 in interpret_addr () 
(gdb) bt 
#0  0x080ec329 in interpret_addr () 
#1  0x080ec462 in interpret_addr2 () 
#2  0x080efbe0 in open_udp_socket () 
#3  0x0810f56c in krb5_set_password () 
#4  0x0810fdbf in kerberos_set_password () 
#5  0x0806b17c in net_ads_password () 
#6  0x08068690 in net_run_function () 
#7  0x0806b51c in net_ads () 
#8  0x08068690 in net_run_function () 
#9  0x080697d3 in main () 
#10 0x42017589 in __libc_start_main () from /lib/i686/libc.so.6 

Thanks, 

James Willard 
james at whispering.org 

-----Original Message----- 
From: samba-technical-admin at lists.samba.org 
[mailto:samba-technical-admin at lists.samba.org] On Behalf Of James 
Willard 
Sent: Friday, November 01, 2002 2:12 PM 
To: samba-technical at samba.org 
Subject: Segfault with "net ads password" 


Hi, 

I'm trying to troubleshoot a problem I've been having for the past 
several weeks with "net ads password" attempting to change a users' 
password. I'm using the Samba 3.0 CVS tree updated this morning (even 
though there has been no difference in behavior in the past month or 
so). I'm running: 

net ads password UserName at DOMAIN.COM -U Admin at REALM.COM%Password 

I receive a prompt: 

Enter new password for UserName at DOMAIN.COM: 

I enter a password and then it segfaults. Below are excerpts from a 
strace: 

... 
write(3, "kadmin", 6)                   = 6 
write(3, "\0\0\0\10", 4)                = 4 
write(3, "changepw", 8)                 = 8 
... 
write(3, "\0\0\0\0", 4)                 = 4 
write(3, NULL, 0)                       = 0 
fcntl64(3, F_SETLKW, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 
0 
close(3)                                = 0 
time(NULL)                              = 1036176903 
gettimeofday({1036176903, 994633}, NULL) = 0 gettimeofday({1036176903, 
995109}, NULL) = 0 
--- SIGSEGV (Segmentation fault) --- 
+++ killed by SIGSEGV +++ 

The operating system is RedHat Linux 7.3 on a PIII with krb5-1.2.5 and 
openldap-2.1.4 

What other information would be useful in tracking down this bug? 

Thanks, 

James Willard 
james at whispering.org 

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