From: Tomasz Blaszczak <tomasz.blaszczak@consult.red>
Date: Wed, 23 Jun 2021 07:17:05 +0000 (+0200)
Subject: When an item is added to an array, then the array is realloc()ed (to size+1),
X-Git-Tag: lxc-5.0.0~151^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe444ea6bcfe65d58a4dc0bef0db0c3372ed12a5;p=thirdparty%2Flxc.git

When an item is added to an array, then the array is realloc()ed (to size+1),
and the item is copied (strdup()) to the array.
Thus, when an item is removed from an array, memory allocated for that item
should be freed, successive items should be left-shifted and the array
realloc()ed again (size-1).

Additional changes:
- If strdup() fails in add_to_array(), then an array should be
  realloc()ed again to original size.
- Initialize an array in list_all_containers().

Signed-off-by: Tomasz Blaszczak <tomasz.blaszczak@consult.red>
---

diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 34149675e..b1be7e0ed 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -2270,8 +2270,10 @@ static bool add_to_array(char ***names, char *cname, int pos)
 
 	*names = newnames;
 	newnames[pos] = strdup(cname);
-	if (!newnames[pos])
+	if (!newnames[pos]) {
+		*names = (char**)realloc(*names, (pos) * sizeof(char *));
 		return false;
+	}
 
 	/* Sort the array as we will use binary search on it. */
 	qsort(newnames, pos + 1, sizeof(char *),
@@ -2320,7 +2322,12 @@ static bool remove_from_array(char ***names, char *cname, int size)
 {
 	char **result = get_from_array(names, cname, size);
 	if (result != NULL) {
-		free(result);
+		int i;
+		for (i = 0; (*names)[i] != *result && i < size; i++) {
+		}
+		free(*result);
+		memmove(*names+i, *names+i+1, (size-i-1) * sizeof(char*));
+		*names = (char**)realloc(*names, (size-1) * sizeof(char *));
 		return true;
 	}
 
@@ -5659,7 +5666,7 @@ int list_all_containers(const char *lxcpath, char ***nret,
 {
 	int i, ret, active_cnt, ct_cnt, ct_list_cnt;
 	char **active_name;
-	char **ct_name;
+	char **ct_name = NULL;
 	struct lxc_container **ct_list = NULL;
 
 	ct_cnt = list_defined_containers(lxcpath, &ct_name, NULL);