r7372: abartet's patch for BUG 2391 (segv caused by free a static pointer)

(This used to be commit 4cda2bd035276bd090bf0fbd4e3b2eff657a80cb)

4 files changed, 46 insertions, 25 deletions

diff --git a/source3/auth/auth_server.c b/source3/auth/auth_server.c
index bc611ec229..7bce32ef2b 100644
--- a/source3/auth/auth_server.c
+++ b/source3/auth/auth_server.c
@@ -384,6 +384,7 @@ use this machine as the password server.\n"));
 			real_username, True )) != NULL ) 
 		{
 			nt_status = make_server_info_pw(server_info, pass->pw_name, pass);
+			passwd_free(&pass);
 		}
 		else
 		{
diff --git a/source3/auth/auth_util.c b/source3/auth/auth_util.c
index 31bfa2fe01..021f780112 100644
--- a/source3/auth/auth_util.c
+++ b/source3/auth/auth_util.c
@@ -958,6 +958,7 @@ static NTSTATUS fill_sam_account(TALLOC_CTX *mem_ctx,
 				 uid_t *uid, gid_t *gid,
 				 SAM_ACCOUNT **sam_account)
 {
+	NTSTATUS nt_status;
 	fstring dom_user, lower_username;
 	fstring real_username;
 	struct passwd *passwd;
@@ -992,7 +993,9 @@ static NTSTATUS fill_sam_account(TALLOC_CTX *mem_ctx,
 	DEBUG(5,("fill_sam_account: located username was [%s]\n",
 		*found_username));
 
-	return pdb_init_sam_pw(sam_account, passwd);
+	nt_status = pdb_init_sam_pw(sam_account, passwd);
+	passwd_free(&passwd);
+	return nt_status;
 }
 
 /****************************************************************************
@@ -1024,7 +1027,7 @@ struct passwd *smb_getpwnam( char *domuser, fstring save_username, BOOL create )
 	if ( p ) {
 		fstring strip_username;
 
-		pw = Get_Pwnam( domuser );
+		pw = Get_Pwnam_alloc( domuser );
 		if ( pw ) {	
 			/* make sure we get the case of the username correct */
 			/* work around 'winbind use default domain = yes' */
@@ -1055,7 +1058,7 @@ struct passwd *smb_getpwnam( char *domuser, fstring save_username, BOOL create )
 	
 	/* just lookup a plain username */
 	
-	pw = Get_Pwnam(username);
+	pw = Get_Pwnam_alloc(username);
 		
 	/* Create local user if requested. */
 	
@@ -1065,7 +1068,7 @@ struct passwd *smb_getpwnam( char *domuser, fstring save_username, BOOL create )
 			return NULL;
 
 		smb_create_user(NULL, username, NULL);
-		pw = Get_Pwnam(username);
+		pw = Get_Pwnam_alloc(username);
 	}
 	
 	/* one last check for a valid passwd struct */
diff --git a/source3/lib/username.c b/source3/lib/username.c
index 317935d396..e691e4c1f1 100644
--- a/source3/lib/username.c
+++ b/source3/lib/username.c
@@ -250,35 +250,16 @@ static struct passwd *Get_Pwnam_internals(const char *user, char *user2)
 done:
 	DEBUG(5,("Get_Pwnam_internals %s find user [%s]!\n",ret ? "did":"didn't", user));
 
-	/* This call used to just return the 'passwd' static buffer.
-	   This could then have accidental reuse implications, so 
-	   we now malloc a copy, and free it in the next use.
-
-	   This should cause the (ab)user to segfault if it 
-	   uses an old struct. 
-	   
-	   This is better than useing the wrong data in security
-	   critical operations.
-
-	   The real fix is to make the callers free the returned 
-	   malloc'ed data.
-	*/
-
-	if (Get_Pwnam_ret) {
-		passwd_free(&Get_Pwnam_ret);
-	}
-	
-	Get_Pwnam_ret = ret;
-
 	return ret;
 }
 
 /****************************************************************************
  Get_Pwnam wrapper without modification.
   NOTE: This with NOT modify 'user'! 
+  This will return an allocated structure
 ****************************************************************************/
 
-struct passwd *Get_Pwnam(const char *user)
+struct passwd *Get_Pwnam_alloc(const char *user)
 {
 	fstring user2;
 	struct passwd *ret;
@@ -298,6 +279,40 @@ struct passwd *Get_Pwnam(const char *user)
 }
 
 /****************************************************************************
+ Get_Pwnam wrapper without modification.
+  NOTE: This with NOT modify 'user'! 
+****************************************************************************/
+
+struct passwd *Get_Pwnam(const char *user)
+{
+	struct passwd *ret;
+
+	ret = Get_Pwnam_alloc(user);
+	
+	/* This call used to just return the 'passwd' static buffer.
+	   This could then have accidental reuse implications, so 
+	   we now malloc a copy, and free it in the next use.
+
+	   This should cause the (ab)user to segfault if it 
+	   uses an old struct. 
+	   
+	   This is better than useing the wrong data in security
+	   critical operations.
+
+	   The real fix is to make the callers free the returned 
+	   malloc'ed data.
+	*/
+
+	if (Get_Pwnam_ret) {
+		passwd_free(&Get_Pwnam_ret);
+	}
+	
+	Get_Pwnam_ret = ret;
+
+	return ret;  
+}
+
+/****************************************************************************
  Check if a user is in a netgroup user list. If at first we don't succeed,
  try lower case.
 ****************************************************************************/
diff --git a/source3/smbd/sesssetup.c b/source3/smbd/sesssetup.c
index 48524b472d..6f963fc603 100644
--- a/source3/smbd/sesssetup.c
+++ b/source3/smbd/sesssetup.c
@@ -267,8 +267,10 @@ static int reply_spnego_kerberos(connection_struct *conn,
 		SAFE_FREE(client);
 		data_blob_free(&ap_rep);
 		data_blob_free(&session_key);
+		passwd_free(&pw);
 		return ERROR_NT(ret);
 	}
+	passwd_free(&pw);
 
         /* make_server_info_pw does not set the domain. Without this we end up
 	 * with the local netbios name in substitutions for %D. */