[bug report] block/rnbd-clt: Dynamically alloc buffer for pathname & blk_symlink_name

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

Hello Md Haris Iqbal,

This is a semi-automatic email about new static checker warnings.

The patch 64e8a6ece1a5: "block/rnbd-clt: Dynamically alloc buffer for
pathname & blk_symlink_name" from Nov 26, 2020, leads to the
following Smatch complaint:

    drivers/block/rnbd/rnbd-clt-sysfs.c:525 rnbd_clt_add_dev_symlink()
    error: uninitialized symbol 'ret'.

    drivers/block/rnbd/rnbd-clt-sysfs.c:524 rnbd_clt_add_dev_symlink()
    error: we previously assumed 'dev->blk_symlink_name' could be null (see line 500)

drivers/block/rnbd/rnbd-clt-sysfs.c
   493  static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
   494  {
   495          struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
   496          int ret, len;
   497  
   498          len = strlen(dev->pathname) + strlen(dev->sess->sessname) + 2;
   499		dev->blk_symlink_name = kzalloc(len, GFP_KERNEL);
   500		if (!dev->blk_symlink_name) {
   501			rnbd_clt_err(dev, "Failed to allocate memory for blk_symlink_name\n");
   502			goto out_err;

ret = -ENOMEM; here

   503		}
   504	
   505		ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name,
   506					      len);
   507		if (ret) {
   508			rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n",
   509				      ret);
   510			goto out_err;
   511		}
   512	
   513		ret = sysfs_create_link(rnbd_devs_kobj, gd_kobj,
   514					dev->blk_symlink_name);
   515		if (ret) {
   516			rnbd_clt_err(dev, "Creating /sys/block symlink failed, err: %d\n",
   517				      ret);
   518			goto out_err;
   519		}
   520	
   521		return 0;
   522	
   523	out_err:
   524		dev->blk_symlink_name[0] = '\0';
                ^^^^^^^^^^^^^^^^^^^^^^^^
This will oops if the kzalloc() fails.

   525		return ret;
   526	}

regards,
dan carpenter