> On Sep 1, 2020, at 7:26 AM, Paul Cercueil <p...@crapouillou.net> wrote:
> 
> The zstd decompression code, as it is right now, will most likely fail
> on 32-bit systems, as the default output buffer size causes the buffer's
> end address to overflow.
> 
> Address this issue by setting a sane default to the default output size,
> with a value that won't overflow the buffer's end address.
> 
> Signed-off-by: Paul Cercueil <p...@crapouillou.net>
> ---
> 
> Notes:
>    v2: Change limit to 1 GiB
> 
>    v3: Compute size limit instead of using hardcoded value
> 
> lib/decompress_unzstd.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/decompress_unzstd.c b/lib/decompress_unzstd.c
> index 0ad2c15479ed..790abc472f5b 100644
> --- a/lib/decompress_unzstd.c
> +++ b/lib/decompress_unzstd.c
> @@ -178,8 +178,13 @@ static int INIT __unzstd(unsigned char *in_buf, long 
> in_len,
>       int err;
>       size_t ret;
> 
> +     /*
> +      * ZSTD decompression code won't be happy if the buffer size is so big
> +      * that its end address overflows. When the size is not provided, make
> +      * it as big as possible without having the end address overflow.
> +      */
>       if (out_len == 0)
> -             out_len = LONG_MAX; /* no limit */
> +             out_len = UINTPTR_MAX - (uintptr_t)out_buf;

Great, that works for me. Thanks for fixing this!

Reviewed-by: Nick Terrell <terre...@fb.com>

>       if (fill == NULL && flush == NULL)
>               /*
> -- 
> 2.28.0
> 

Reply via email to