Fix crash with absurdly but not impossibly deeply nested device stacks

[fio.git] / diskutil.c

diff --git a/diskutil.c b/diskutil.c
index d98e39a50b0d6423febdf0457f5097718ad53382..3681dde5d8cedb8190e4dcbd61f60274bba76179 100644 (file)
--- a/diskutil.c
+++ b/diskutil.c
@@ -276,13 +276,20 @@ static struct disk_util *disk_util_add(struct thread_data *td, int majdev,
 {
        struct disk_util *du, *__du;
        struct flist_head *entry;
+       int l;
 
        dprint(FD_DISKUTIL, "add maj/min %d/%d: %s\n", majdev, mindev, path);
 
        du = smalloc(sizeof(*du));
        memset(du, 0, sizeof(*du));
        INIT_FLIST_HEAD(&du->list);
-       sprintf(du->path, "%s/stat", path);
+       l = snprintf(du->path, sizeof(du->path), "%s/stat", path);
+       if (l < 0 || l >= sizeof(du->path)) {
+               log_err("constructed path \"%.100s[...]/stat\" larger than buffer (%zu bytes)\n",
+                       path, sizeof(du->path) - 1);
+               sfree(du);
+               return NULL;
+       }
        strncpy((char *) du->dus.name, basename(path), FIO_DU_NAME_SZ);
        du->sysfs_root = path;
        du->major = majdev;
@@ -658,7 +665,7 @@ void show_disk_util(int terse, struct json_object *parent)
        if (!terse)
                log_info("\nDisk stats (read/write):\n");
 
-       if (terse && terse_version == 4) {
+       if (output_format == FIO_OUTPUT_JSON) {
                array = json_create_array();
                json_object_add_value_array(parent, "disk_util", array);
        }
@@ -667,7 +674,7 @@ void show_disk_util(int terse, struct json_object *parent)
                du = flist_entry(entry, struct disk_util, list);
 
                aggregate_slaves_stats(du);
-               if (terse && terse_version == 4)
+               if (output_format == FIO_OUTPUT_JSON)
                        print_disk_util_json(du, array);
                else
                        print_disk_util(&du->dus, &du->agg, terse);