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ALSA: compress: prevent potential divide by zero bugs 

The problem is seen in the q6asm_dai_compr_set_params() function:

	ret = q6asm_map_memory_regions(dir, prtd->audio_client, prtd->phys,
				       (prtd->pcm_size / prtd->periods),
                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
				       prtd->periods);

In this code prtd->pcm_size is the buffer_size and prtd->periods comes
from params->buffer.fragments.  If we allow the number of fragments to
be zero then it results in a divide by zero bug.  One possible fix would
be to use prtd->pcm_count directly instead of using the division to
re-calculate it.  But I decided that it doesn't really make sense to
allow zero fragments.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Dan Carpenter 2018-12-21 12:06:58 +03:00 committed by Mark Brown
parent a41d9dbf5d
commit 678e2b44c8
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1 changed files with 2 additions and 1 deletions
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3
sound/core/compress_offload.c
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@ -541,7 +541,8 @@ 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 > INT_MAX / params->buffer.fragment_size)
params->buffer.fragments > INT_MAX / params->buffer.fragment_size ||
params->buffer.fragments == 0)
return -EINVAL;
/* now codec parameters */