diff --git a/src/ftp.c b/src/ftp.c
index 7c0996f..35f1f9c 100644
--- a/src/ftp.c
+++ b/src/ftp.c
@@ -85,8 +85,10 @@ typedef struct client_struct client_t;
 static client_t *clients[MAX_CLIENTS] = {NULL};
 
 void set_ftp_password(char *new_password) {
-    if (password)
+    if (password) {
         free(password);
+        password = NULL;
+    }
     if (new_password) {
         password = malloc(strlen(new_password) + 1);
         if (!password)
@@ -114,6 +116,7 @@ static int32_t write_reply(client_t *client, uint16_t code, char *msg) {
     console_printf("Wrote reply: %s", msgbuf);
     int32_t ret = send_exact(client->socket, msgbuf, msglen);
     free(msgbuf);
+    msgbuf = NULL;
     return ret;
 }
 
@@ -532,8 +535,9 @@ static int32_t stor_or_append(client_t *client, FILE *f) {
 static int32_t ftp_STOR(client_t *client, char *path) {
     FILE *f = vrt_fopen(client->cwd, path, "wb");
     int fd;
-    if (f)
+    if (f) {
         fd = fileno(f);
+    }
     if (f && client->restart_marker && lseek(fd, client->restart_marker, SEEK_SET) != client->restart_marker) {
         int32_t lseek_error = errno;
         fclose(f);
@@ -726,6 +730,7 @@ static void cleanup_client(client_t *client) {
         }
     }
     free(client);
+    client = NULL;
     num_clients--;
     console_printf("Client disconnected.\n");
 }
@@ -785,6 +790,7 @@ static bool process_accept_events(int32_t server) {
             console_printf("Error writing greeting.\n");
             network_close_blocking(peer);
             free(client);
+            client = NULL;
         } else {
             for (client_index = 0; client_index < MAX_CLIENTS; client_index++) {
                 if (!clients[client_index]) {
diff --git a/src/net.c b/src/net.c
index 0b51495..9312be7 100644
--- a/src/net.c
+++ b/src/net.c
@@ -252,9 +252,11 @@ int32_t send_from_file(int32_t s, FILE *f) {
         goto end;
     }
     free(buf);
+    buf = NULL;
     return -EAGAIN;
 end:
     free(buf);
+    buf = NULL;
     return result;
 }
 
@@ -274,15 +276,18 @@ int32_t recv_to_file(int32_t s, FILE *f) {
                 goto try_again_with_smaller_buffer;
             }
             free(buf);
+            buf = NULL;
             return bytes_read;
         } else if (bytes_read == 0) {
             free(buf);
+            buf = NULL;
             return 0;
         }
 
         int32_t bytes_written = fwrite(buf, 1, bytes_read, f);
         if (bytes_written < bytes_read) {
             free(buf);
+            buf = NULL;
             return -1;
         }
     }
diff --git a/src/virtualpath.c b/src/virtualpath.c
index c9f82d2..46af373 100644
--- a/src/virtualpath.c
+++ b/src/virtualpath.c
@@ -124,6 +124,7 @@ void AddVirtualFSVOLPath(const char *name, const char *alias, const char *prefix
     VIRTUAL_PARTITION *tmp = realloc(VIRTUAL_FS_VOL, sizeof(VIRTUAL_PARTITION) * (MAX_VIRTUAL_FS_VOL + 1));
     if (!tmp) {
         free(VIRTUAL_FS_VOL);
+        VIRTUAL_FS_VOL     = NULL;
         MAX_VIRTUAL_FS_VOL = 0;
         return;
     }
@@ -157,35 +158,43 @@ void UnmountVirtualPaths() {
     for (i = 0; i < MAX_VIRTUAL_PARTITIONS; i++) {
         if (VIRTUAL_PARTITIONS[i].name) {
             free(VIRTUAL_PARTITIONS[i].name);
+            VIRTUAL_PARTITIONS[i].name = NULL;
         }
         if (VIRTUAL_PARTITIONS[i].alias) {
             free(VIRTUAL_PARTITIONS[i].alias);
+            VIRTUAL_PARTITIONS[i].name = NULL;
         }
         if (VIRTUAL_PARTITIONS[i].prefix) {
             free(VIRTUAL_PARTITIONS[i].prefix);
+            VIRTUAL_PARTITIONS[i].prefix = NULL;
         }
     }
 
     for (i = 0; i < MAX_VIRTUAL_FS_VOL; i++) {
         if (VIRTUAL_FS_VOL[i].name) {
             free(VIRTUAL_FS_VOL[i].name);
+            VIRTUAL_FS_VOL[i].name = NULL;
         }
     }
 
     for (i = 0; i < MAX_VIRTUAL_FS; i++) {
         if (VIRTUAL_FS[i].name) {
             free(VIRTUAL_FS[i].name);
+            VIRTUAL_FS[i].name = NULL;
         }
     }
 
     if (VIRTUAL_PARTITIONS) {
         free(VIRTUAL_PARTITIONS);
+        VIRTUAL_PARTITIONS = NULL;
     }
     if (VIRTUAL_FS_VOL) {
         free(VIRTUAL_FS_VOL);
+        VIRTUAL_FS_VOL = NULL;
     }
     if (VIRTUAL_FS) {
         free(VIRTUAL_FS);
+        VIRTUAL_FS = NULL;
     }
     VIRTUAL_PARTITIONS     = NULL;
     VIRTUAL_FS_VOL         = NULL;
diff --git a/src/vrt.c b/src/vrt.c
index 8a44c72..4664ee0 100644
--- a/src/vrt.c
+++ b/src/vrt.c
@@ -98,7 +98,10 @@ static char *virtual_abspath(char *virtual_cwd, char *virtual_path) {
     }
 
 end:
-    if (path != virtual_path) free(path);
+    if (path != virtual_path) {
+        free(path);
+        path = NULL;
+    }
     return normalised_path;
 }
 
@@ -156,6 +159,7 @@ char *to_real_path(char *virtual_cwd, char *virtual_path) {
 
 end:
     free(virtual_path);
+    virtual_path = NULL;
     return path;
 }
 
@@ -219,6 +223,7 @@ static void *with_virtual_path(void *virtual_cwd, void *void_f, char *virtual_pa
     }
 
     free(path);
+    path = NULL;
     return result;
 }
 
@@ -236,6 +241,7 @@ int vrt_stat(char *cwd, char *path, struct stat *st) {
         return 0;
     }
     free(real_path);
+    real_path = NULL;
     return (int) with_virtual_path(cwd, stat, path, -1, st, NULL);
 }
 
@@ -251,6 +257,7 @@ static int vrt_checkdir(char *cwd, char *path) {
         return 0;
     }
     free(real_path);
+    real_path = NULL;
     return (int) with_virtual_path(cwd, checkdir, path, -1, NULL);
 }
 
@@ -267,6 +274,7 @@ int vrt_chdir(char *cwd, char *path) {
     strcpy(cwd, abspath);
     if (cwd[1]) strcat(cwd, "/");
     free(abspath);
+    abspath = NULL;
     return 0;
 }
 
@@ -283,6 +291,7 @@ int vrt_rename(char *cwd, char *from_path, char *to_path) {
     if (!real_to_path || !*real_to_path) return -1;
     int result = (int) with_virtual_path(cwd, rename, from_path, -1, real_to_path, NULL);
     free(real_to_path);
+    real_to_path = NULL;
     return result;
 }
 
@@ -297,6 +306,7 @@ DIR_P *vrt_opendir(char *cwd, char *path) {
     if (!iter) {
         if (*real_path != 0) {
             free(real_path);
+            real_path = NULL;
         }
         return NULL;
     }
@@ -311,6 +321,7 @@ DIR_P *vrt_opendir(char *cwd, char *path) {
         if (!iter->dir) {
             // root path is not allocated
             free(iter);
+            iter = NULL;
             return NULL;
         }
         memset(iter->dir, 0, sizeof(DIR));
@@ -330,7 +341,9 @@ DIR_P *vrt_opendir(char *cwd, char *path) {
     iter->dir = with_virtual_path(cwd, opendir, path, 0, NULL);
     if (!iter->dir) {
         free(iter->path);
+        iter->path = NULL;
         free(iter);
+        iter = NULL;
         return NULL;
     }
 
@@ -378,17 +391,22 @@ int vrt_closedir(DIR_P *iter) {
     if (!iter) return -1;
 
     if (iter->dir) {
-        if (iter->virt_root)
+        if (iter->virt_root) {
             free(iter->dir);
-        else
+            iter->dir = NULL;
+        } else {
             closedir(iter->dir);
+        }
     }
 
     // root path is not allocated
-    if (iter->path && *iter->path != 0)
+    if (iter->path && *iter->path != 0) {
         free(iter->path);
+        iter->path = NULL;
+    }
 
     free(iter);
+    iter = NULL;
 
     return 0;
 }