Re: [PATCH] android/client: Fix memory leak while using realloc()

[Vinicius Costa Gomes <vinicius.gomes@intel.com>]

Hi,

Atul Rai <a.rai@samsung.com> writes:

> While reallocating space to store additional "remote device set" using
> realloc, if realloc() fails, the original block is left untouched but
> reference to that block is lost as NULL is assigned to remote_devices.
> The original block needs to be freed before return.
> ---
>  android/client/if-bt.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/android/client/if-bt.c b/android/client/if-bt.c
> index 4723024..4249f78 100644
> --- a/android/client/if-bt.c
> +++ b/android/client/if-bt.c
> @@ -94,6 +94,7 @@ static int remote_devices_capacity = 0;
>  void add_remote_device(const bt_bdaddr_t *addr)
>  {
>  	int i;
> +	bt_bdaddr_t *tmp;
>
>  	if (remote_devices == NULL) {
>  		remote_devices = malloc(4 * sizeof(bt_bdaddr_t));
> @@ -119,9 +120,16 @@ void add_remote_device(const bt_bdaddr_t *addr)
>  	/* Realloc space if needed */
>  	if (remote_devices_cnt >= remote_devices_capacity) {

I would move 'tmp' declaration here. Makes it clear that it is only used
in this context.

Apart from that, looks OK.

>  		remote_devices_capacity *= 2;
> +		/*
> +		 * Save reference to previously allocated memory block so that
> +		 * it can be freed in case realloc fails.
> +		 */
> +		tmp = remote_devices;
> +
>  		remote_devices = realloc(remote_devices, sizeof(bt_bdaddr_t) *
>  						remote_devices_capacity);
>  		if (remote_devices == NULL) {
> +			free(tmp);
>  			remote_devices_capacity = 0;
>  			remote_devices_cnt = 0;
>  			return;
> --
> 2.1.4


Cheers,
--
Vinicius