2.2.0 crash at a strange location

Stefan Winter stefan.winter at restena.lu
Mon May 6 10:48:10 CEST 2013


Hi again,

running with -X I get:

rlm_sql_mysql: query:  (SELECT id, username, attribute, value, op FROM check_smtp_ssha1 WHERE username='someusername')
[sql-smtp-hash] User found in radcheck table
rlm_sql (sql-smtp-hash): Released sql socket id: 1
+++[sql-smtp-hash] returns ok
++- policy redundant returns ok
[pap] Normalizing SSHA1-Password from base64 encoding
++[pap] returns updated
Found Auth-Type = PAP
# Executing group from file /usr/local/freeradius/config/raddb/sites-enabled/SMTP
+- entering group PAP {...}
++- entering policy pap_hash_debugfallback {...}
+++- entering group  {...}
[pap] login attempt with password "eq346ici"
[pap] Using SSHA encryption.
[pap] Normalizing SSHA1-Password from base64 encoding
Segmentation fault

Which is before the linelog is reached, so *maybe* the source of the problem is in the base64 normalisation code?

Stefan

On 06.05.2013 10:30, Stefan Winter wrote:
> Hi,
> 
> today I did some minor config changes which turned my stable-running
> 2.2.0 into a crash-every-5-min server :-(
> 
> The change involved 
> a) switching from Cleartext-Password to SSHA1-Password (retaining the
>    pap module for checking the PW validity)
> b) a somewhat sophisticated unlang statement to express: if the SSHA1-PW
>    was wrong, retrieve an alternative password from a VSA 
>    ("RESTENA-Debug-Password") and set it to be the Cleartext-Password;
>    then try pap again with that
> 
> This is obviously the implementation of a "backdoor" for our helpdesk
> if we need to login into a user's account for debugging without knowing
> his actual password because it's SSHA'ed in the DB.
> 
> All nice and cute, and it worked while doing "mild" usage with a test
> account - but now in production things go down the drain with it.
> 
> I've temporarily switched back to the previous SQL query which had
> Cleartext-Password. And voilà: the server is stable again. Even with
> the unlang construct still in place (below for reference).
> 
> So I strongly suspect things to go wrong *only if* SSHA1-Passwords
> are used to authenticate the user. 
> 
> Strangely enough, the gdb backtrace shows that it fails somewhere inside
> glibc while trying to expand a %S in xlat - which appears totally
> unrelated to the changes I did. The backtrace is below.
> 
> policy.conf: replacement for authenticate/pap:
> 
> policy {
> 
>         pap_hash_debugfallback {
>                 group {
>                         pap {
>                                 reject = 2
>                                 ok = return
>                         }
> 
>                         if ( "%{control:RESTENA-Debug-Password}" ) {
>                                 update control {
>                                         SSHA1-Password !* "nogood"
>                                         NT-Password !* "nogood"
>                                         Cleartext-Password := "%{control:RESTENA-Debug-Password}"
>                                 }
>                                 ok = 1 
>                                 ok
>                         }
>                         
>                         pap {
>                                 reject = 2
>                                 ok = return
>                         }
>                 }
>         }
> ...
> }
> 
> 
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0x4b015950 (LWP 24837)]
> 0x00002b380d7d5550 in ?? () from /lib64/libc.so.6
> (gdb) bt
> #0  0x00002b380d7d5550 in ?? () from /lib64/libc.so.6
> #1  0x00002b380d7d6c0c in malloc () from /lib64/libc.so.6
> #2  0x00002b380d7da8f2 in strdup () from /lib64/libc.so.6
> #3  0x00002b380d7ed928 in ?? () from /lib64/libc.so.6
> #4  0x00002b380d7ee3f0 in tzset () from /lib64/libc.so.6
> #5  0x00002b380d7f2c94 in strftime_l () from /lib64/libc.so.6
> #6  0x000000000042277d in radius_xlat (out=0x4b013a30 "[Access-Accept", outlen=1023, fmt=0x667c4e "[%S] [AUTH OK   ] '%{User-Name}' (%{RESTENA-Service-Type}:%{client:shortname})", request=0x2aaab0001f60, 
>     func=0x2aaaab2e33d0 <linelog_escape_func>) at xlat.c:1348
> #7  0x00002aaaab2e31d4 in do_linelog (instance=0x835a60, request=0x2aaab0001f60) at rlm_linelog.c:328
> #8  0x000000000041c920 in modcall (component=7, c=<value optimized out>, request=0x2aaab0001f60) at modcall.c:304
> #9  0x0000000000419be8 in indexed_modcall (comp=0, idx=0, request=0x2aaab0001f60) at modules.c:740
> #10 0x00000000004094fd in rad_postauth (request=0x2aaab0001f60) at auth.c:433
> #11 0x0000000000409b83 in rad_authenticate (request=0x2aaab0001f60) at auth.c:831
> #12 0x0000000000427538 in radius_handle_request (request=0x2aaab0001f60, fun=0x409540 <rad_authenticate>) at event.c:3784
> #13 0x0000000000420728 in request_handler_thread (arg=<value optimized out>) at threads.c:537
> #14 0x00002b380c8d8020 in start_thread () from /lib64/libpthread.so.0
> #15 0x00002b380d829f8d in clone () from /lib64/libc.so.6
> #16 0x0000000000000000 in ?? ()
> (gdb) bt full
> #0  0x00002b380d7d5550 in ?? () from /lib64/libc.so.6
> No symbol table info available.
> #1  0x00002b380d7d6c0c in malloc () from /lib64/libc.so.6
> No symbol table info available.
> #2  0x00002b380d7da8f2 in strdup () from /lib64/libc.so.6
> No symbol table info available.
> #3  0x00002b380d7ed928 in ?? () from /lib64/libc.so.6
> No symbol table info available.
> #4  0x00002b380d7ee3f0 in tzset () from /lib64/libc.so.6
> No symbol table info available.
> #5  0x00002b380d7f2c94 in strftime_l () from /lib64/libc.so.6
> No symbol table info available.
> #6  0x000000000042277d in radius_xlat (out=0x4b013a30 "[Access-Accept", outlen=1023, fmt=0x667c4e "[%S] [AUTH OK   ] '%{User-Name}' (%{RESTENA-Service-Type}:%{client:shortname})", request=0x2aaab0001f60, 
>     func=0x2aaaab2e33d0 <linelog_escape_func>) at xlat.c:1348
>         c = <value optimized out>
>         len = <value optimized out>
>         freespace = <value optimized out>
>         p = 0x667c50 "S] [AUTH OK   ] '%{User-Name}' (%{RESTENA-Service-Type}:%{client:shortname})"
>         q = 0x4b013a31 "Access-Accept"
>         tmp = (VALUE_PAIR *) 0x2aaab0001f60
>         TM = (struct tm *) 0x3
>         s_TM = {tm_sec = 45, tm_min = 15, tm_hour = 10, tm_mday = 6, tm_mon = 4, tm_year = 113, tm_wday = 1, tm_yday = 125, tm_isdst = 1, tm_gmtoff = 7200, tm_zone = 0x807da0 "CEST"}
>         tmpdt = "\000\020\000\000\000\000\000\000\000\020\000\000\000\000\000\000\b\000\000\000\000\000\000\000\236A�G", '\0' <repeats 11 times>
> #7  0x00002aaaab2e31d4 in do_linelog (instance=0x835a60, request=0x2aaab0001f60) at rlm_linelog.c:328
>         ci = <value optimized out>
>         cp = <value optimized out>
>         fd = 56
>         buffer = "/var/log/radius/activity.log\000+\000\000�*\001K\001\000\000\000�+\001K\000\000\000\000�X\001K\000\000\000\000\000�\213\000\000\000\000\000\005\000\000\000\000\000\000\000�>\000��*\000\000\000\000\000\000\000\000\000\000�>\000��*\000\000\n\000\000\000\000\000\000\000�>\000��*\000\000P>\001K\000\000\000\000�w�\0178+\000\000:=\000\000\000\000\000\000\030", '\0' <repeats 15 times>, "�\025B\000\000\000\000\000\000�\213\000\000\000\000\000�*\001K\000\000\000\000P>\001K\000\000\000\000`\037\000��*\000\000\000\000\002\000\000\000\000\000\220�\213\000\000"...
>         p = <value optimized out>
>         line = "[Access-Accept", '\0' <repeats 434 times>, "Mon May  6 10:15:45 2013\000\000\000\000\000\000\000\000Mon May  6 10:15:45 2013", '\0' <repeats 116 times>, "\024\000\000\000`\001\000\000\000\000\000\0008\001\000\000\000\000\000\000\000\000\000\000\024", '\0' <repeats 35 times>, "\202\230'\f8+\000\000`\003j\000\000\000\000\000 \000\000��*\000\0008\001", '\0' <repeats 14 times>, "\001\000\000\000\000\000\000\000`\037\000��*\000\0000}\203\000\000\000\000\000\fl}\r8+\000\000�\204|", '\0' <repeats 13 times>...
>         value = 0x667c4e "[%S] [AUTH OK   ] '%{User-Name}' (%{RESTENA-Service-Type}:%{client:shortname})"
>         gid = <value optimized out>
>         grp = (struct group *) 0x0
>         endptr = 0x6889fc ")"
> #8  0x000000000041c920 in modcall (component=7, c=<value optimized out>, request=0x2aaab0001f60) at modcall.c:304
>         server = <value optimized out>
>         myresult = 1
>         stack = {pointer = 0, priority = {0, 0, 3, 0, 0, 0, 0, 0, 0, 3, 0, 3, 0 <repeats 20 times>}, result = {7, 7, 2, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0 <repeats 19 times>}, children = {0x8f2910, 0x8f2730, 0x8f2800, 0x0, 
>     0x837410, 0x0 <repeats 27 times>}, start = {0x0, 0x8f2730, 0x8f27a0, 0x0, 0x0, 0x837480, 0x8374f0, 0x8af080, 0x8e3ec0, 0x0 <repeats 23 times>}}
>         parent = (modcallable *) 0x8f2730
>         child = (modcallable *) 0x8f2800
>         if_taken = 0
>         was_if = 0
> #9  0x0000000000419be8 in indexed_modcall (comp=0, idx=0, request=0x2aaab0001f60) at modules.c:740
>         this = <value optimized out>
>         rcode = <value optimized out>
>         list = (modcallable *) 0x8f2910
>         server = (virtual_server_t *) 0x837330
> #10 0x00000000004094fd in rad_postauth (request=0x2aaab0001f60) at auth.c:433
>         result = <value optimized out>
>         postauth_type = 0
>         vp = (VALUE_PAIR *) 0x0
> #11 0x0000000000409b83 in rad_authenticate (request=0x2aaab0001f60) at auth.c:831
>         namepair = (VALUE_PAIR *) 0x9a71f0
>         check_item = (VALUE_PAIR *) 0x0
>         auth_item = (VALUE_PAIR *) 0x9a8c10
>         module_msg = <value optimized out>
>         tmp = (VALUE_PAIR *) 0x0
>         result = -1275060192
>         autz_retry = <value optimized out>
>         autz_type = <value optimized out>
> #12 0x0000000000427538 in radius_handle_request (request=0x2aaab0001f60, fun=0x409540 <rad_authenticate>) at event.c:3784
> ---Type <return> to continue, or q <return> to quit---
> No locals.
> #13 0x0000000000420728 in request_handler_thread (arg=<value optimized out>) at threads.c:537
>         fun = (RAD_REQUEST_FUNP) 0x409540 <rad_authenticate>
>         self = (THREAD_HANDLE *) 0x2aaab4001fe0
> #14 0x00002b380c8d8020 in start_thread () from /lib64/libpthread.so.0
> No symbol table info available.
> #15 0x00002b380d829f8d in clone () from /lib64/libc.so.6
> No symbol table info available.
> #16 0x0000000000000000 in ?? ()
> No symbol table info available.
> (gdb)
> 
> 
> 
> -
> List info/subscribe/unsubscribe? See http://www.freeradius.org/list/devel.html
> 


-- 
Stefan WINTER
Ingenieur de Recherche
Fondation RESTENA - Réseau Téléinformatique de l'Education Nationale et de la Recherche
6, rue Richard Coudenhove-Kalergi
L-1359 Luxembourg

Tel: +352 424409 1
Fax: +352 422473

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