At Wed, 16 Jul 2014 09:37:04 +0300, Dan Carpenter wrote:
I previously added an integer overflow check here but looking at it now, it's still buggy.
The bug happens in snd_compr_allocate_buffer(). We multiply ".fragments" and ".fragment_size" and that doesn't overflow but then we save it in an unsigned int so it truncates the high bits away and we allocate a smaller than expected size.
Fixes: b35cc8225845 ('ALSA: compress_core: integer overflow in snd_compr_allocate_buffer()') Signed-off-by: Dan Carpenter dan.carpenter@oracle.com
The other option would be to declare buffer_size as size_t instead of an unsigned int. This feels like a safer fix though.
Agreed, I took the patch now as is. Thanks.
Takashi
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index 7403f34..89028fa 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -491,7 +491,7 @@ static int snd_compress_check_input(struct snd_compr_params *params) { /* first let's check the buffer parameter's */ if (params->buffer.fragment_size == 0 ||
params->buffer.fragments > SIZE_MAX / params->buffer.fragment_size)
params->buffer.fragments > INT_MAX / params->buffer.fragment_size)return -EINVAL;
/* now codec parameters */