groupdb: Use wrapper for string to integer conversion

In order to detect an value overflow error during
the string to integer conversion with strtoul/strtoull,
the errno variable must be set to zero before the execution and
checked after the conversion is performed. This is achieved by
using the wrapper function strtoul_err and strtoull_err.

Signed-off-by: Swen Schillig <swen@linux.ibm.com>
Reviewed-by: Ralph Böhme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

1 files changed, 10 insertions, 1 deletions

diff --git a/source3/groupdb/mapping.c b/source3/groupdb/mapping.c
index 43722e777d4..77eb0d6e5cd 100644
--- a/source3/groupdb/mapping.c
+++ b/source3/groupdb/mapping.c
@@ -208,6 +208,7 @@ int smb_create_group(const char *unix_group, gid_t *new_gid)
 	char *add_script = NULL;
 	int 	ret = -1;
 	int 	fd = 0;
+	int error = 0;
 
 	*new_gid = 0;
 
@@ -244,7 +245,15 @@ int smb_create_group(const char *unix_group, gid_t *new_gid)
 			nread = read(fd, output, sizeof(output)-1);
 			if (nread > 0) {
 				output[nread] = '\0';
-				*new_gid = (gid_t)strtoul(output, NULL, 10);
+				*new_gid = (gid_t)strtoul_err(output,
+							      NULL,
+							      10,
+							      &error);
+				if (error != 0) {
+					*new_gid = 0;
+					close(fd);
+					return -1;
+				}
 			}
 
 			close(fd);