PAM crash on a trusted system ....

Robert Currey — Fri, 20 Oct 2006 13:56:36 GMT

The sample program attached will crash somewhere inside a pam module ...

Notes ...
* If the program is NOT compiled with -lpthread, it will not crash (but our app does need -lpthread)
* If the program doesn't _compile_ the following it also will not crash ...
#if 1
void
crash_it(char* user)
{
struct spwd* spwd = getspnam(user);
//endspent();
}
#endif
NOTE: This code is NEVER executed, simply been compiled).

Here's a stack trace from the execution of the sample program ...

conversation_handler: msg[0]: Please enter user name: (prompt)
conversation_handler: response=root
fatal signal: 10
( 0) 0x00026590 segv_handler__Fi + 0x2c [./auth_test]
( 1) 0x00079e80 _sigreturn [./auth_test]
( 2) 0xc000a200 what_string.c
/ux/core/libs/libnss_files/shared_pa1
ccom options = -DA1.1 -DS1. + 0x3201 [/usr/lib/libnss_files.1]
( 3) 0xc000d7b4 _nss_files_shadow_constr + 0xc4 [/usr/lib/libnss_files.1]
( 4) 0x00072a48 __nss_search + 0x170 [./auth_test]
( 5) 0xc0052c30 nss_getprpwnam_r + 0x90 [/usr/lib/libsec.2]
( 6) 0xc004c814 nss_getprpwnam + 0xb4 [/usr/lib/libsec.2]
( 7) 0xc0e1326c print_pwd_change_info + 0x4c [/usr/lib/security/libpam_unix.1]
( 8) 0xc0e09b28 pam_sm_authenticate + 0x278 [/usr/lib/security/libpam_unix.1]
( 9) 0xc07f98c4 pam_authenticate + 0xbc [/usr/lib/libpam.1]
(10) 0x0002681c main + 0xb0 [./auth_test]
(11) 0x00050b0c _start + 0x98 [./auth_test]
(12) 0x00025418 $START$ + 0x178 [./auth_test]
Bus error (core dumped)

Some more info ... (a very generic HP11.00 machine put into trusted mode and using a std pam.conf)

# uname -a
HP-UX breen B.11.00 A 9000/785 2010146131 two-user license

# cat /etc/pam.conf
#
# PAM Configuration
#
# Account Management
#
dtaction account required /usr/lib/security/libpam_unix.1
dtlogin account required /usr/lib/security/libpam_unix.1
ftp account required /usr/lib/security/libpam_unix.1
login account required /usr/lib/security/libpam_unix.1
su account required /usr/lib/security/libpam_unix.1
OTHER account required /usr/lib/security/libpam_unix.1
#
# Authentication Management
#
dtaction auth required /usr/lib/security/libpam_unix.1
dtlogin auth required /usr/lib/security/libpam_unix.1
ftp auth required /usr/lib/security/libpam_unix.1
login auth required /usr/lib/security/libpam_unix.1
su auth required /usr/lib/security/libpam_unix.1
OTHER auth required /usr/lib/security/libpam_unix.1
#
# Password Management
#
dtaction password required /usr/lib/security/libpam_unix.1
dtlogin password required /usr/lib/security/libpam_unix.1
login password required /usr/lib/security/libpam_unix.1
passwd password required /usr/lib/security/libpam_unix.1
OTHER password required /usr/lib/security/libpam_unix.1
#
# Session Management
#
dtaction session required /usr/lib/security/libpam_unix.1
dtlogin session required /usr/lib/security/libpam_unix.1
login session required /usr/lib/security/libpam_unix.1
OTHER session required /usr/lib/security/libpam_unix.1

Re: PAM crash on a trusted system ....

Dennis Handly — Thu, 21 Jun 2007 00:52:21 GMT

I couldn't duplicate your abort, possibly because I'm not on a trusted system.

You are illegally linking a aC++ application with -lpthread without compiling with -mt. This is especially bad with -AA.

Also you are linking with archive system libs, which is never a good thing if you have a mixture of some shared:
-Wl,-aarchive_shared

topic PAM crash on a trusted system .... in Operating System - Linux

PAM crash on a trusted system ....

Re: PAM crash on a trusted system ....