From d2e8ad3f8fcb3dcabb56ce9b5e7fada6800cfc77 Mon Sep 17 00:00:00 2001 From: Jakub Hrozek Date: Fri, 12 Apr 2013 12:01:01 +0200 Subject: LDAP: do not invalidate pointer with realloc while processing ghost users https://fedorahosted.org/sssd/ticket/1799 One peculiarity of the sysdb_attrs_get_el interface is that if the attribute does not exist, then the attrs array is reallocated and the element is created. But in case other pointers are already pointing into the array, the realloc might invalidate them. Such case was in the sdap_process_ghost_members function where if the group had no members, the "gh" pointer requested earlier might have been invalidated by the realloc in order to create the member element. --- src/providers/ldap/sdap_async_groups.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/providers/ldap/sdap_async_groups.c b/src/providers/ldap/sdap_async_groups.c index 9d4a8487..bb88d6c4 100644 --- a/src/providers/ldap/sdap_async_groups.c +++ b/src/providers/ldap/sdap_async_groups.c @@ -323,10 +323,20 @@ sdap_process_ghost_members(struct sysdb_attrs *attrs, return ret; } - ret = sysdb_attrs_get_el(attrs, + ret = sysdb_attrs_get_el_ext(attrs, opts->group_map[SDAP_AT_GROUP_MEMBER].sys_name, - &memberel); - if (ret != EOK) { + false, &memberel); + if (ret == ENOENT) { + /* Create a dummy element with no values in order for the loop to just + * fall through and make sure the attrs array is not reallocated. + */ + memberel = talloc(attrs, struct ldb_message_element); + if (memberel == NULL) { + return ENOMEM; + } + memberel->num_values = 0; + memberel->values = NULL; + } else if (ret != EOK) { DEBUG(SSSDBG_MINOR_FAILURE, ("Error reading members: [%s]\n", strerror(ret))); return ret; -- cgit