Catch possible bad input passed in by glibc

Seen in tests and was leading to a segfault

2 files changed, 20 insertions, 0 deletions

diff --git a/sss_client/group.c b/sss_client/group.c
index 61b1e487b..675b8b71e 100644
--- a/sss_client/group.c
+++ b/sss_client/group.c
@@ -66,6 +66,8 @@ static void sss_nss_getgrent_data_clean(void) {
  *  0-3: 32bit number gid
  *  4-7: 32bit unsigned number of members
  *  8-X: sequence of 0 terminated strings (name, passwd, mem..)
+ *
+ *  FIXME: do we need to pad so that each result is 32 bit aligned ?
  */
 struct sss_nss_gr_rep {
     struct group *result;
@@ -239,6 +241,9 @@ enum nss_status _nss_sss_getgrnam_r(const char *name, struct group *result,
     enum nss_status nret;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     rd.len = strlen(name) + 1;
     rd.data = name;
 
@@ -286,6 +291,9 @@ enum nss_status _nss_sss_getgrgid_r(gid_t gid, struct group *result,
     uint32_t group_gid;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     group_gid = gid;
     rd.len = sizeof(uint32_t);
     rd.data = &group_gid;
@@ -352,6 +360,9 @@ enum nss_status _nss_sss_getgrent_r(struct group *result,
     uint32_t num_entries;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     /* if there are leftovers return the next one */
     if (sss_nss_getgrent_data.data != NULL &&
         sss_nss_getgrent_data.ptr < sss_nss_getgrent_data.len) {
diff --git a/sss_client/passwd.c b/sss_client/passwd.c
index e999e5dd5..0d70b6843 100644
--- a/sss_client/passwd.c
+++ b/sss_client/passwd.c
@@ -180,6 +180,9 @@ enum nss_status _nss_sss_getpwnam_r(const char *name, struct passwd *result,
     enum nss_status nret;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     rd.len = strlen(name) + 1;
     rd.data = name;
 
@@ -227,6 +230,9 @@ enum nss_status _nss_sss_getpwuid_r(uid_t uid, struct passwd *result,
     uint32_t user_uid;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     user_uid = uid;
     rd.len = sizeof(uint32_t);
     rd.data = &user_uid;
@@ -294,6 +300,9 @@ enum nss_status _nss_sss_getpwent_r(struct passwd *result,
     uint32_t num_entries;
     int ret;
 
+    /* Caught once glibc passing in buffer == 0x0 */
+    if (!buffer || !buflen) return ERANGE;
+
     /* if there are leftovers return the next one */
     if (sss_nss_getpwent_data.data != NULL &&
         sss_nss_getpwent_data.ptr < sss_nss_getpwent_data.len) {