| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.20 05/88] ALSA: compress: prevent potential divide by zero bugs | Date | Mon, 4 Mar 2019 09:21:48 +0100 |
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4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 678e2b44c8e3fec3afc7202f1996a4500a50be93 ]
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> Signed-off-by: Sasha Levin <sashal@kernel.org> --- sound/core/compress_offload.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index 26b5e245b0747..8b78ddffa509a 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -529,7 +529,8 @@ 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 */ -- 2.19.1
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