* [patch] ALSA: compress: fix an integer overflow check
@ 2014-07-16 6:37 ` Dan Carpenter
0 siblings, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2014-07-16 6:37 UTC (permalink / raw)
To: Vinod Koul; +Cc: Jaroslav Kysela, Takashi Iwai, alsa-devel, kernel-janitors
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.
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 */
^ permalink raw reply related [flat|nested] 4+ messages in thread* [patch] ALSA: compress: fix an integer overflow check
@ 2014-07-16 6:37 ` Dan Carpenter
0 siblings, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2014-07-16 6:37 UTC (permalink / raw)
To: Vinod Koul; +Cc: Jaroslav Kysela, Takashi Iwai, alsa-devel, kernel-janitors
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.
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 */
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [patch] ALSA: compress: fix an integer overflow check
2014-07-16 6:37 ` Dan Carpenter
@ 2014-07-16 14:34 ` Takashi Iwai
-1 siblings, 0 replies; 4+ messages in thread
From: Takashi Iwai @ 2014-07-16 14:34 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Vinod Koul, Jaroslav Kysela, alsa-devel, kernel-janitors
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 */
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] ALSA: compress: fix an integer overflow check
@ 2014-07-16 14:34 ` Takashi Iwai
0 siblings, 0 replies; 4+ messages in thread
From: Takashi Iwai @ 2014-07-16 14:34 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Vinod Koul, Jaroslav Kysela, alsa-devel, kernel-janitors
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 */
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-07-16 14:34 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2014-07-16 6:37 [patch] ALSA: compress: fix an integer overflow check Dan Carpenter
2014-07-16 6:37 ` Dan Carpenter
2014-07-16 14:34 ` Takashi Iwai
2014-07-16 14:34 ` Takashi Iwai
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