My patch to fe-connect.c introduced a new bug which is triggered only, if

scrappy · scrappy · commit c13ef1afed3c · 1996-07-27T02:27:55.000Z
Kerberos is being used (attempt to free static memory).
The error was caused by a confusing doublespeak of fe_getauthname():
Returns a pointer to static memory, if you authenticate via Kerberos,
a pointer to dynamic memory otherwise.

Submitted by: Erich Stamberger &lt;eberger@gewi.kfunigraz.ac.at&gt;
diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-auth.c,v 1.2 1996/07/23 03:35:11 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-auth.c,v 1.3 1996/07/27 02:27:55 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -500,14 +500,15 @@ fe_getauthsvc(char* PQerrormsg)
 }
 
 /*
- * fe_getauthname -- returns a pointer to static space containing whatever
+ * fe_getauthname -- returns a pointer to dynamic space containing whatever
  *		     name the user has authenticated to the system
  * if there is an error, return the error message in PQerrormsg
  */
 char*
 fe_getauthname(char* PQerrormsg)
 {
     char *name = (char *) NULL;
+    char *authn = (char *) NULL;
     MsgType authsvc;
     
     authsvc = fe_getauthsvc(PQerrormsg);
@@ -525,11 +526,7 @@ fe_getauthname(char* PQerrormsg)
     case STARTUP_MSG:
 	{
 	    struct passwd *pw = getpwuid(geteuid());
-	    if (pw &&
-		pw->pw_name &&
-		(name = (char *) malloc(strlen(pw->pw_name) + 1))) {
-		(void) strcpy(name, pw->pw_name);
-	    }
+	    if (pw) name = pw->pw_name;
 	}
 	break;
     default:
@@ -538,7 +535,10 @@ fe_getauthname(char* PQerrormsg)
 		       authsvc);
 	break;
     }
-    return(name);
+
+    if(name && (authn = (char *) malloc(strlen(name) + 1)))
+      (void) strcpy(authn, name);
+    return(authn);
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@`
`7`	`7`	`*`
`8`	`8`	`*`
`9`	`9`	`* IDENTIFICATION`
`10`		`- * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-auth.c,v 1.2 1996/07/23 03:35:11 scrappy Exp $`
	`10`	`+ * $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-auth.c,v 1.3 1996/07/27 02:27:55 scrappy Exp $`
`11`	`11`	`*`
`12`	`12`	`*-------------------------------------------------------------------------`
`13`	`13`	`*/`
`@@ -500,14 +500,15 @@ fe_getauthsvc(char* PQerrormsg)`
`500`	`500`	`}`
`501`	`501`
`502`	`502`	`/*`
`503`		`- * fe_getauthname -- returns a pointer to static space containing whatever`
	`503`	`+ * fe_getauthname -- returns a pointer to dynamic space containing whatever`
`504`	`504`	`* name the user has authenticated to the system`
`505`	`505`	`* if there is an error, return the error message in PQerrormsg`
`506`	`506`	`*/`
`507`	`507`	`char*`
`508`	`508`	`fe_getauthname(char* PQerrormsg)`
`509`	`509`	`{`
`510`	`510`	`char name = (char ) NULL;`
	`511`	`+ char authn = (char ) NULL;`
`511`	`512`	`MsgType authsvc;`
`512`	`513`
`513`	`514`	`authsvc = fe_getauthsvc(PQerrormsg);`
`@@ -525,11 +526,7 @@ fe_getauthname(char* PQerrormsg)`
`525`	`526`	`case STARTUP_MSG:`
`526`	`527`	`{`
`527`	`528`	`struct passwd *pw = getpwuid(geteuid());`
`528`		`- if (pw &&`
`529`		`- pw->pw_name &&`
`530`		`- (name = (char *) malloc(strlen(pw->pw_name) + 1))) {`
`531`		`- (void) strcpy(name, pw->pw_name);`
`532`		`- }`
	`529`	`+ if (pw) name = pw->pw_name;`
`533`	`530`	`}`
`534`	`531`	`break;`
`535`	`532`	`default:`
`@@ -538,7 +535,10 @@ fe_getauthname(char* PQerrormsg)`
`538`	`535`	`authsvc);`
`539`	`536`	`break;`
`540`	`537`	`}`
`541`		`- return(name);`
	`538`	`+`
	`539`	`+ if(name && (authn = (char *) malloc(strlen(name) + 1)))`
	`540`	`+ (void) strcpy(authn, name);`
	`541`	`+ return(authn);`
`542`	`542`	`}`
`543`	`543`
`544`	`544`