ACK: [PATCH] uefi: uefidump: free original string on failed realloc

[Alex Hung]

On 2017-04-13 03:08 AM, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> A common bug is where realloc fails to allocate and we assume that
> the memory being realloc'd was freed. This is not the case, the
> NULL return means we need to free the original string to avoid
> a memory leak.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  src/uefi/uefidump/uefidump.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/src/uefi/uefidump/uefidump.c b/src/uefi/uefidump/uefidump.c
> index 90556204..305d2d6a 100644
> --- a/src/uefi/uefidump/uefidump.c
> +++ b/src/uefi/uefidump/uefidump.c
> @@ -83,9 +83,13 @@ static char *uefidump_vprintf(char *str, const char *fmt, ...)
>  	if (str == NULL)
>  		str = strdup(buffer);
>  	else {
> -		str = realloc(str, strlen(str) + strlen(buffer) + 1);
> -		if (str == NULL)
> +		char *tmp;
> +		tmp = realloc(str, strlen(str) + strlen(buffer) + 1);
> +		if (!tmp) {
> +			free(str);
>  			return NULL;
> +		}
> +		str = tmp;
>  		strcat(str, buffer);
>  	}
>
>


Acked-by: Alex Hung <alex.hung at canonical.com>