[patch] pairmake_any() segfaults at conffile parse time if attr not in dictionary

[John Morrissey]

When referencing non-dictionary attrs in FreeRADIUS' config
("Vendor-6969-Attr-69", for example), pairmake() calls pairmake_any().

FreeRADIUS 2.1.8's pairmake_any() assumes a non-NULL value argument, causing
this segfault:

#0  0x00007f2ec4c99010 in strlen () from /lib/libc.so.6
#1  0x00007f2ec5ffa495 in pairmake (attribute=<value optimized out>, value=0x0, operator=9)
    at valuepair.c:1358
#2  0x000000000040c8ba in cf_pairtovp (pair=0xe7d430) at conffile.c:1860
#3  0x000000000041abda in do_compile_modsingle (parent=0x0, component=2, 
    ci=<value optimized out>, grouptype=0, modname=0x7ffff741e128) at modcall.c:1351
#4  0x0000000000418273 in load_component_section (cs=0xe7d0f0, components=0x11a5580, comp=2)
    at modules.c:873
#5  0x0000000000418828 in load_byserver (cs=0xe7cbd0) at modules.c:1072
#6  0x0000000000418b57 in virtual_servers_load (config=0xc71030) at modules.c:1200
#7  0x0000000000419518 in setup_modules (reload=<value optimized out>, config=0xc71030)
    at modules.c:1467
#8  0x0000000000417926 in read_mainconfig (reload=<value optimized out>) at mainconfig.c:914
#9  0x000000000041c1d8 in main (argc=2, argv=<value optimized out>) at radiusd.c:257

This patch modifies pairmake_any() to short-circuit in the case of a NULL
value, allowing cf_pairtovp() to continue as normal, updating the type and
value fields.

--- src/lib/valuepair.c~	2010-01-21 15:54:56.681161000 +0000
+++ src/lib/valuepair.c	2010-01-21 15:55:06.687350000 +0000
@@ -1355,6 +1355,12 @@
 		return NULL;
 	}
 
+	vp->operator = (operator == 0) ? T_OP_EQ : operator;
+
+	if (!value) {
+		return vp;
+	}
+
 	size = strlen(value + 2);
 
 	/*
@@ -1397,8 +1402,6 @@
 		break;
 	}
        
-	vp->operator = (operator == 0) ? T_OP_EQ : operator;
-
 	return vp;
 }
 

john
-- 
John Morrissey          _o            /\         ----  __o
jwm at horde.net        _-< \_          /  \       ----  <  \,
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