lxc/0113-Malloc-parameter-check-and-judgment.patch

From 3b2dff6c4d17c6adeba8304f30334e93db611233 Mon Sep 17 00:00:00 2001
From: liuhao <liuhao27@huawei.com>
Date: Thu, 4 Jul 2019 12:08:17 +0800
Subject: [PATCH 113/140] Malloc parameter check and judgment

Signed-off-by: wujing <wujing50@huawei.com>
Signed-off-by: LiFeng <lifeng68@huawei.com>
---
 src/lxc/attach.c                               |  2 +-
 src/lxc/commands.c                             |  9 ++-
 src/lxc/conf.c                                 | 20 ++++--
 src/lxc/confile.c                              |  8 +--
 src/lxc/json/container_start_generate_config.c | 12 +++-
 src/lxc/json/defs.c                            |  8 +++
 src/lxc/json/json_common.c                     | 97 +++++++++-----------------
 src/lxc/json/logger_json_file.c                |  6 +-
 src/lxc/lxccontainer.c                         | 12 +++-
 src/lxc/path.c                                 |  8 ++-
 src/lxc/start.c                                |  6 +-
 src/lxc/terminal.c                             |  2 +-
 src/lxc/utils.c                                |  4 +-
 13 files changed, 104 insertions(+), 90 deletions(-)

diff --git a/src/lxc/attach.c b/src/lxc/attach.c
index d7b16e3..ac4bd39 100644
--- a/src/lxc/attach.c
+++ b/src/lxc/attach.c
@@ -1188,7 +1188,7 @@ static int create_attach_timeout_thread(int64_t attach_timeout, pid_t pid)
 	struct attach_timeout_conf *timeout_conf = NULL;
 
 	timeout_conf = malloc(sizeof(struct attach_timeout_conf));
-	if (!timeout_conf) {
+	if (timeout_conf == NULL) {
 		ERROR("Failed to malloc attach timeout conf");
 		ret = -1;
 		goto out;
diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 0802a16..fa02a4b 100644
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -1075,11 +1075,16 @@ int lxc_cmd_set_terminal_fifos(const char *name, const char *lxcpath, const char
 	const char *cmd_out_fifo = out_fifo ? out_fifo : none_fifo_name;
 	const char *cmd_err_fifo = err_fifo ? err_fifo : none_fifo_name;
 
+	if (len + strlen(cmd_in_fifo) + strlen(split) + strlen(cmd_out_fifo) +
+	     strlen(split) + strlen(cmd_err_fifo) == SIZE_MAX)
+		return -1;
 	len += strlen(cmd_in_fifo) + strlen(split) + strlen(cmd_out_fifo) + strlen(split) + strlen(cmd_err_fifo) + 1;
 	tmp = malloc(len);
-	if (!tmp)
+	if (tmp == NULL)
+		return -1;
+	ret = snprintf(tmp, len, "%s%s%s%s%s", cmd_in_fifo, split, cmd_out_fifo, split, cmd_err_fifo);
+	if (ret < 0)
 		return -1;
-	snprintf(tmp, len, "%s%s%s%s%s", cmd_in_fifo, split, cmd_out_fifo, split, cmd_err_fifo);
 
 	struct lxc_cmd_rr cmd = {
 		.req = {
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 996d267..3ecccbd 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -4393,7 +4393,11 @@ int lxc_drop_caps(struct lxc_conf *conf)
 
 	// caplist[i] is 1 if we keep capability i
 	caplist = malloc(numcaps * sizeof(int));
-	memset(caplist, 0, numcaps * sizeof(int));
+	if (caplist == NULL) {
+		ERROR("Out of memory");
+		return -1;
+	}
+	(void)memset(caplist, 0, numcaps * sizeof(int));
 
 	lxc_list_for_each(iterator, caps) {
 
@@ -4488,8 +4492,8 @@ static char* generate_json_str(const char *name, const char *lxcpath, const char
 		cpid = "-1";
 	}
 
-	if ((SIZE_MAX - strlen(name) - strlen(cpid) - strlen(rootfs) - strlen(lxcpath) - strlen(name)) <
-	                (strlen("{\"ociVersion\":\"\",\"id\":\"\",\"pid\":,\"root\":\"\",\"bundle\":\"\"}") + 1 + 1)) {
+	if ((strlen(name) + strlen(cpid) + strlen(rootfs) + strlen(lxcpath) + strlen(name)) >
+	       SIZE_MAX - (strlen("{\"ociVersion\":\"\",\"id\":\"\",\"pid\":,\"root\":\"\",\"bundle\":\"\"}") - 1 - 1)) {
 		ERROR("Out of memory");
 		ret = -1;
 		goto out_free;
@@ -4499,7 +4503,7 @@ static char* generate_json_str(const char *name, const char *lxcpath, const char
 	size = strlen("{\"ociVersion\":\"\",\"id\":\"\",\"pid\":,\"root\":\"\",\"bundle\":\"\"}") +
 	       strlen(name) + strlen(cpid) + strlen(rootfs) + strlen(lxcpath) + 1 + strlen(name) + 1;
 	inmsg = malloc(size);
-	if (!inmsg) {
+	if (inmsg == NULL) {
 		ERROR("Out of memory");
 		ret = -1;
 		goto out_free;
@@ -4531,9 +4535,11 @@ static char **merge_ocihook_env(char **oldenvs, size_t env_len, size_t *merge_en
 	                   };
 	char *lxcenv_buf = NULL;
 
+	if (result_len > SIZE_MAX - (sizeof(lxc_envs) / sizeof(char *)) - 1)
+		return NULL;
 	result_len += (sizeof(lxc_envs) / sizeof(char *)) + 1;
 	result = malloc(sizeof(char *) * result_len);
-	if (!result)
+	if (result == NULL)
 		return NULL;
 	memset(result, 0, sizeof(char *) * result_len);
 
@@ -4552,7 +4558,7 @@ static char **merge_ocihook_env(char **oldenvs, size_t env_len, size_t *merge_en
 			}
 			env_buf_len = ((strlen(tmpenv) + 1) + strlen(lxc_envs[j])) + 1;
 			lxcenv_buf = malloc(env_buf_len);
-			if (!lxcenv_buf) {
+			if (lxcenv_buf == NULL) {
 				lxc_free_array((void **)result, free);
 				return NULL;
 			}
@@ -4759,7 +4765,7 @@ static int run_ocihook_buffer(struct oci_hook_conf *oconf, const char *inmsg)
 	}
 
 	conf = malloc(sizeof(struct wait_conf));
-	if (!conf) {
+	if (conf == NULL) {
 		SYSERROR("Failed to malloc.");
 		goto on_error;
 	}
diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index 8a082d5..a75e023 100644
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -2318,13 +2318,13 @@ static int set_config_populate_device(const char *key, const char *value,
 
 	/* allocate list element */
 	dev_list = malloc(sizeof(*dev_list));
-	if (!dev_list)
+	if (dev_list == NULL)
 		goto on_error;
 
 	lxc_list_init(dev_list);
 
 	dev_elem = malloc(sizeof(*dev_elem));
-	if (!dev_elem)
+	if (dev_elem == NULL)
 		goto on_error;
 	memset(dev_elem, 0, sizeof(*dev_elem));
 
@@ -2362,7 +2362,7 @@ static int set_config_rootfs_masked_paths(const char *key, const char *value,
 		return lxc_clear_rootfs_masked_paths(lxc_conf);
 
 	list_item = malloc(sizeof(*list_item));
-	if (!list_item)
+	if (list_item == NULL)
 		goto on_error;
 
 	list_item->elem = safe_strdup(value);
@@ -2387,7 +2387,7 @@ static int set_config_rootfs_ro_paths(const char *key, const char *value,
 		return lxc_clear_rootfs_ro_paths(lxc_conf);
 
 	list_item = malloc(sizeof(*list_item));
-	if (!list_item)
+	if (list_item == NULL)
 		goto on_error;
 
 	list_item->elem = safe_strdup(value);
diff --git a/src/lxc/json/container_start_generate_config.c b/src/lxc/json/container_start_generate_config.c
index 5ec8311..3748973 100644
--- a/src/lxc/json/container_start_generate_config.c
+++ b/src/lxc/json/container_start_generate_config.c
@@ -41,6 +41,11 @@ container_start_generate_config *make_container_start_generate_config(yajl_val t
         if (tmp != NULL && YAJL_GET_ARRAY(tmp) != NULL && YAJL_GET_ARRAY(tmp)->len > 0) {
             size_t i;
             ret->additional_gids_len = YAJL_GET_ARRAY(tmp)->len;
+            if (YAJL_GET_ARRAY(tmp)->len > SIZE_MAX / sizeof(*ret->additional_gids) - 1) {
+                *err = safe_strdup("invalid additional gids size");
+                free_container_start_generate_config(ret);
+                return NULL;
+            }
             ret->additional_gids = safe_malloc((YAJL_GET_ARRAY(tmp)->len + 1) * sizeof(*ret->additional_gids));
             for (i = 0; i < YAJL_GET_ARRAY(tmp)->len; i++) {
                 yajl_val val = YAJL_GET_ARRAY(tmp)->values[i];
@@ -233,8 +238,13 @@ char *container_start_generate_config_generate_json(container_start_generate_con
         goto free_out;
     }
 
+    if (gen_len == SIZE_MAX) {
+        *err = safe_strdup("Invalid buffer length");
+        goto free_out;
+    }
+
     json_buf = safe_malloc(gen_len + 1);
-	(void)memcpy(json_buf, gen_buf, gen_len);
+    (void)memcpy(json_buf, gen_buf, gen_len);
     json_buf[gen_len] = '\0';
 
 free_out:
diff --git a/src/lxc/json/defs.c b/src/lxc/json/defs.c
index 8a052a8..4bf569a 100644
--- a/src/lxc/json/defs.c
+++ b/src/lxc/json/defs.c
@@ -24,6 +24,10 @@ defs_hook *make_defs_hook(yajl_val tree, struct parser_context *ctx, parser_erro
         if (tmp != NULL && YAJL_GET_ARRAY(tmp) != NULL && YAJL_GET_ARRAY(tmp)->len > 0) {
             size_t i;
             ret->args_len = YAJL_GET_ARRAY(tmp)->len;
+            if (YAJL_GET_ARRAY(tmp)->len > SIZE_MAX / sizeof(*ret->args) - 1) {
+                free_defs_hook(ret);
+                return NULL;
+            }
             ret->args = safe_malloc((YAJL_GET_ARRAY(tmp)->len + 1) * sizeof(*ret->args));
             for (i = 0; i < YAJL_GET_ARRAY(tmp)->len; i++) {
                 yajl_val val = YAJL_GET_ARRAY(tmp)->values[i];
@@ -39,6 +43,10 @@ defs_hook *make_defs_hook(yajl_val tree, struct parser_context *ctx, parser_erro
         if (tmp != NULL && YAJL_GET_ARRAY(tmp) != NULL && YAJL_GET_ARRAY(tmp)->len > 0) {
             size_t i;
             ret->env_len = YAJL_GET_ARRAY(tmp)->len;
+            if (YAJL_GET_ARRAY(tmp)->len > SIZE_MAX / sizeof(*ret->env) - 1) {
+                free_defs_hook(ret);
+                return NULL;
+            }
             ret->env = safe_malloc((YAJL_GET_ARRAY(tmp)->len + 1) * sizeof(*ret->env));
             for (i = 0; i < YAJL_GET_ARRAY(tmp)->len; i++) {
                 yajl_val val = YAJL_GET_ARRAY(tmp)->values[i];
diff --git a/src/lxc/json/json_common.c b/src/lxc/json/json_common.c
index 5da1e6d..ed2fe83 100755
--- a/src/lxc/json/json_common.c
+++ b/src/lxc/json/json_common.c
@@ -445,6 +445,9 @@ json_map_int_int *make_json_map_int_int(yajl_val src, struct parser_context *ctx
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(int) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(int));
@@ -505,16 +508,8 @@ int append_json_map_int_int(json_map_int_int *map, int key, int val) {
     vals = safe_malloc(len * sizeof(int));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(int)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(int)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(int));
+        (void)memcpy(vals, map->values, map->len * sizeof(int));
     }
     free(map->keys);
     map->keys = keys;
@@ -591,6 +586,9 @@ json_map_int_bool *make_json_map_int_bool(yajl_val src, struct parser_context *c
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(int) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(int));
@@ -646,16 +644,8 @@ int append_json_map_int_bool(json_map_int_bool *map, int key, bool val) {
     vals = safe_malloc(len * sizeof(bool));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(int)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(bool)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(int));
+        (void)memcpy(vals, map->values, map->len * sizeof(bool));
     }
     free(map->keys);
     map->keys = keys;
@@ -733,6 +723,9 @@ json_map_int_string *make_json_map_int_string(yajl_val src, struct parser_contex
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(char *) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(int));
@@ -786,16 +779,8 @@ int append_json_map_int_string(json_map_int_string *map, int key, const char *va
     vals = safe_malloc(len * sizeof(char *));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(int)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(char *)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(int));
+        (void)memcpy(vals, map->values, map->len * sizeof(char *));
     }
     free(map->keys);
     map->keys = keys;
@@ -864,6 +849,9 @@ json_map_string_int *make_json_map_string_int(yajl_val src, struct parser_contex
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(char *) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(char *));
@@ -913,16 +901,8 @@ int append_json_map_string_int(json_map_string_int *map, const char *key, int va
     vals = safe_malloc(len * sizeof(int));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(char *)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(int)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(char *));
+        (void)memcpy(vals, map->values, map->len * sizeof(int));
     }
     free(map->keys);
     map->keys = keys;
@@ -991,6 +971,9 @@ json_map_string_bool *make_json_map_string_bool(yajl_val src, struct parser_cont
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(char *) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(char *));
@@ -1017,6 +1000,7 @@ json_map_string_bool *make_json_map_string_bool(yajl_val src, struct parser_cont
     }
     return ret;
 }
+
 int append_json_map_string_bool(json_map_string_bool *map, const char *key, bool val) {
     size_t len;
     char **keys = NULL;
@@ -1035,16 +1019,8 @@ int append_json_map_string_bool(json_map_string_bool *map, const char *key, bool
     vals = safe_malloc(len * sizeof(bool));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(char *)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(bool)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(char *));
+        (void)memcpy(vals, map->values, map->len * sizeof(bool));
     }
     free(map->keys);
     map->keys = keys;
@@ -1114,6 +1090,9 @@ json_map_string_string *make_json_map_string_string(yajl_val src, struct parser_
     if (src != NULL && YAJL_GET_OBJECT(src) != NULL) {
         size_t i;
         size_t len = YAJL_GET_OBJECT(src)->len;
+        if (len > SIZE_MAX / sizeof(char *) - 1) {
+            return NULL;
+        }
         ret = safe_malloc(sizeof(*ret));
         ret->len = len;
         ret->keys = safe_malloc((len + 1) * sizeof(char *));
@@ -1149,9 +1128,9 @@ int append_json_map_string_string(json_map_string_string *map, const char *key,
 
     for (i = 0; i < map->len; i++) {
         if (strcmp(map->keys[i], key) == 0) {
-                free(map->values[i]);
-                map->values[i] = safe_strdup(val ? val : "");
-                return 0;
+            free(map->values[i]);
+            map->values[i] = safe_strdup(val ? val : "");
+            return 0;
         }
     }
 
@@ -1164,16 +1143,8 @@ int append_json_map_string_string(json_map_string_string *map, const char *key,
     vals = safe_malloc(len * sizeof(char *));
 
     if (map->len) {
-        if (memcpy(keys, map->keys, map->len * sizeof(char *)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
-        if (memcpy(vals, map->values, map->len * sizeof(char *)) != NULL) {
-            free(keys);
-            free(vals);
-            return -1;
-        }
+        (void)memcpy(keys, map->keys, map->len * sizeof(char *));
+        (void)memcpy(vals, map->values, map->len * sizeof(char *));
     }
     free(map->keys);
     map->keys = keys;
diff --git a/src/lxc/json/logger_json_file.c b/src/lxc/json/logger_json_file.c
index 842d35b..6abeef4 100644
--- a/src/lxc/json/logger_json_file.c
+++ b/src/lxc/json/logger_json_file.c
@@ -230,8 +230,12 @@ char *logger_json_file_generate_json(logger_json_file *ptr, struct parser_contex
 		goto free_out;
 	}
 
+	if (gen_len == SIZE_MAX) {
+		*err = safe_strdup("Invalid buffer length");
+		goto free_out;
+	}
 	json_buf = safe_malloc(gen_len + 1);
-	memcpy(json_buf, gen_buf, gen_len);
+	(void)memcpy(json_buf, gen_buf, gen_len);
 	json_buf[gen_len] = '\0';
 
 free_out:
diff --git a/src/lxc/lxccontainer.c b/src/lxc/lxccontainer.c
index 3b2c5af..5a72483 100644
--- a/src/lxc/lxccontainer.c
+++ b/src/lxc/lxccontainer.c
@@ -928,6 +928,9 @@ static char **use_init_args(char **init_argv, size_t init_args)
 
 	do {
 		argv = malloc(sizeof(char *));
+		if (argv == NULL) {
+			return NULL;
+		}
 	} while (!argv);
 
 	argv[0] = NULL;
@@ -3378,9 +3381,12 @@ static bool set_oci_hook_config_filename(struct lxc_container *c)
 		return false;
 
 	/* $lxc_path + "/" + c->name + "/" + "config" + '\0' */
+	if (strlen(c->config_path) + strlen(c->name) > SIZE_MAX - strlen(OCI_HOOK_JSON_FILE_NAME) - 3)
+		return false;
 	len = strlen(c->config_path) + strlen(c->name) + strlen(OCI_HOOK_JSON_FILE_NAME) + 3;
+
 	newpath = malloc(len);
-	if (!newpath)
+	if (newpath == NULL)
 		return false;
 
 	ret = snprintf(newpath, len, "%s/%s/%s", c->config_path, c->name, OCI_HOOK_JSON_FILE_NAME);
@@ -5276,11 +5282,11 @@ static int set_start_extral_configs(struct lxc_container *c)
 
 	if (lconf == NULL) {
 		c->lxc_conf = malloc(sizeof(struct lxc_conf));
-		lconf = c->lxc_conf;
-		if (lconf == NULL) {
+		if (c->lxc_conf == NULL) {
 			fprintf(stderr, "Out of memory\n");
 			return -1;
 		}
+		lconf = c->lxc_conf;
 	}
 	if (snprintf(fpath, PATH_MAX, "%s/%s/%s", c->config_path, c->name, START_GENERATE_CONFIG) < 0) {
 		fprintf(stderr, "Sprintf config path failed\n");
diff --git a/src/lxc/path.c b/src/lxc/path.c
index c545887..df285f5 100644
--- a/src/lxc/path.c
+++ b/src/lxc/path.c
@@ -58,7 +58,7 @@ char *preserve_trailing_dot_or_separator(const char *cleanedpath,
 
 	len = strlen(cleanedpath) + 3;
 	respath = malloc(len);
-	if (!respath) {
+	if (respath == NULL) {
 		ERROR("Out of memory");
 		return NULL;
 	}
@@ -90,12 +90,16 @@ bool filepath_split(const char *path, char **dir, char **base)
 	size_t len;
 
 	len = strlen(path);
+	if (len >= PATH_MAX) {
+		ERROR("Invalid path");
+		return false;
+	}
 	i = len - 1;
 	while (i >= 0 && path[i] != '/')
 		i--;
 
 	*dir = malloc(i + 2);
-	if (!*dir) {
+	if (*dir == NULL) {
 		ERROR("Out of memory");
 		return false;
 	}
diff --git a/src/lxc/start.c b/src/lxc/start.c
index d6c706e..00d478c 100644
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -2383,7 +2383,7 @@ static int create_start_timeout_thread(struct lxc_conf *conf, unsigned int start
 	}
 
 	timeout_conf = malloc(sizeof(struct start_timeout_conf));
-	if (!timeout_conf) {
+	if (timeout_conf == NULL) {
 		ERROR("Failed to malloc start timeout conf");
 		ret = -1;
 		goto out;
@@ -2657,7 +2657,7 @@ static struct lxc_handler *lxc_init_clean_handler(char *name, char *lxcpath, str
 	struct lxc_handler *handler;
 
 	handler = malloc(sizeof(*handler));
-	if (!handler)
+	if (handler == NULL)
 		return NULL;
 
 	memset(handler, 0, sizeof(*handler));
@@ -2707,7 +2707,7 @@ static struct lxc_handler *lxc_init_pids_handler(char *name, char *lxcpath, stru
 	struct lxc_handler *handler;
 
 	handler = malloc(sizeof(*handler));
-	if (!handler)
+	if (handler == NULL)
 		return NULL;
 
 	memset(handler, 0, sizeof(*handler));
diff --git a/src/lxc/terminal.c b/src/lxc/terminal.c
index b9b65c6..1fee651 100644
--- a/src/lxc/terminal.c
+++ b/src/lxc/terminal.c
@@ -1330,7 +1330,7 @@ static int lxc_terminal_set_fifo(struct lxc_terminal *console, const char *in, c
 	}
 
 	fifo_elem = malloc(sizeof(*fifo_elem));
-	if (!fifo_elem) {
+	if (fifo_elem == NULL) {
 		if (fifofd_in >= 0)
 			close(fifofd_in);
 		if (fifofd_out >= 0)
diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index e6e8905..656df4a 100644
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -1945,9 +1945,9 @@ static proc_t *lxc_stat2proc(const char *S)
 	*tmp = '\0';			/* replace trailing ')' with NUL */
 
 	P = malloc(sizeof(proc_t));
-	if (!P)
+	if (P == NULL)
 		return NULL;
-	memset(P, 0x00, sizeof(proc_t));
+	(void)memset(P, 0x00, sizeof(proc_t));
 
 	/* parse these two strings separately, skipping the leading "(". */
 	num = sscanf(S, "%d (%15c", &P->pid, P->cmd);   /* comm[16] in kernel */
-- 
1.8.3.1