nat: Bail out if the regexp fails to compile and avoid a crash

If the regexp fails to compile the internal dfa is NULL and a
regexec will crash nicely. Fail and free the string if the regexp
fails to compile.

1 files changed, 8 insertions, 4 deletions

diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index 3158f3472..3a5068e26 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -467,7 +467,8 @@ DEFUN(cfg_nat_ussd_query,
       "Set the USSD query to match with the ussd-list-name\n"
       "The query to match")
 {
-	bsc_parse_reg(_nat, &_nat->ussd_query_re, &_nat->ussd_query, argc, argv);
+	if (bsc_parse_reg(_nat, &_nat->ussd_query_re, &_nat->ussd_query, argc, argv) != 0)
+		return CMD_WARNING;
 	return CMD_SUCCESS;
 }
 
@@ -580,7 +581,8 @@ DEFUN(cfg_lst_imsi_allow,
 	if (!entry)
 		return CMD_WARNING;
 
-	bsc_parse_reg(acc, &entry->imsi_allow_re, &entry->imsi_allow, argc - 1, &argv[1]);
+	if (bsc_parse_reg(acc, &entry->imsi_allow_re, &entry->imsi_allow, argc - 1, &argv[1]) != 0)
+		return CMD_WARNING;
 	return CMD_SUCCESS;
 }
 
@@ -602,7 +604,8 @@ DEFUN(cfg_lst_imsi_deny,
 	if (!entry)
 		return CMD_WARNING;
 
-	bsc_parse_reg(acc, &entry->imsi_deny_re, &entry->imsi_deny, argc - 1, &argv[1]);
+	if (bsc_parse_reg(acc, &entry->imsi_deny_re, &entry->imsi_deny, argc - 1, &argv[1]) != 0)
+		return CMD_WARNING;
 	return CMD_SUCCESS;
 }
 
@@ -710,7 +713,8 @@ DEFUN(test_regex, test_regex_cmd,
 	char *str = NULL;
 
 	memset(&reg, 0, sizeof(reg));
-	bsc_parse_reg(_nat, &reg, &str, 1, argv);
+	if (bsc_parse_reg(_nat, &reg, &str, 1, argv) != 0)
+		return CMD_WARNING;
 
 	vty_out(vty, "String matches allow pattern: %d%s",
 		regexec(&reg, argv[1], 0, NULL, 0) == 0, VTY_NEWLINE);