From: Dan Carpenter Date: Fri, 21 Dec 2018 09:06:58 +0000 (+0300) Subject: ALSA: compress: prevent potential divide by zero bugs X-Git-Tag: v5.0-rc4~26^2~1^2~17 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=678e2b44c8e3fec3afc7202f1996a4500a50be93;p=linux.git 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 Signed-off-by: Mark Brown --- diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index a5b09e75e787..f7d2b373da0a 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -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 */