[PATCH] ALSA: echoaudio: Fix memory allocation

[PATCH] ALSA: echoaudio: Fix memory allocation

[Christophe JAILLET]

'commpage_bak' is allocated with 'sizeof(struct echoaudio)' bytes.
We then copy 'sizeof(struct comm_page)' bytes in it.
On my system, smatch complains because one is 2960 and the other is 3072.

This would result in memory corruption or a oops.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 sound/pci/echoaudio/echoaudio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c
index 1cb85ae..286f5e3 100644
--- a/sound/pci/echoaudio/echoaudio.c
+++ b/sound/pci/echoaudio/echoaudio.c
@@ -2200,11 +2200,11 @@ static int snd_echo_resume(struct device *dev)
 	u32 pipe_alloc_mask;
 	int err;
 
-	commpage_bak = kmalloc(sizeof(struct echoaudio), GFP_KERNEL);
+	commpage_bak = kmalloc(sizeof(*commpage), GFP_KERNEL);
 	if (commpage_bak == NULL)
 		return -ENOMEM;
 	commpage = chip->comm_page;
-	memcpy(commpage_bak, commpage, sizeof(struct comm_page));
+	memcpy(commpage_bak, commpage, sizeof(*commpage));
 
 	err = init_hw(chip, chip->pci->device, chip->pci->subsystem_device);
 	if (err < 0) {
-- 
2.7.4

Re: [PATCH] ALSA: echoaudio: Fix memory allocation

[Takashi Iwai]

On Mon, 27 Jun 2016 21:06:51 +0200,
Christophe JAILLET wrote:
> 
> 'commpage_bak' is allocated with 'sizeof(struct echoaudio)' bytes.
> We then copy 'sizeof(struct comm_page)' bytes in it.
> On my system, smatch complains because one is 2960 and the other is 3072.
> 
> This would result in memory corruption or a oops.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Applied, thanks.


Takashi

Re: [PATCH] ALSA: echoaudio: Fix memory allocation

[walter harms]

Am 27.06.2016 21:06, schrieb Christophe JAILLET:
> 'commpage_bak' is allocated with 'sizeof(struct echoaudio)' bytes.
> We then copy 'sizeof(struct comm_page)' bytes in it.
> On my system, smatch complains because one is 2960 and the other is 3072.
> 
> This would result in memory corruption or a oops.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  sound/pci/echoaudio/echoaudio.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c
> index 1cb85ae..286f5e3 100644
> --- a/sound/pci/echoaudio/echoaudio.c
> +++ b/sound/pci/echoaudio/echoaudio.c
> @@ -2200,11 +2200,11 @@ static int snd_echo_resume(struct device *dev)
>  	u32 pipe_alloc_mask;
>  	int err;
>  
> -	commpage_bak = kmalloc(sizeof(struct echoaudio), GFP_KERNEL);
> +	commpage_bak = kmalloc(sizeof(*commpage), GFP_KERNEL);
>  	if (commpage_bak == NULL)
>  		return -ENOMEM;
>  	commpage = chip->comm_page;
> -	memcpy(commpage_bak, commpage, sizeof(struct comm_page));
> +	memcpy(commpage_bak, commpage, sizeof(*commpage));
>  
>  	err = init_hw(chip, chip->pci->device, chip->pci->subsystem_device);
>  	if (err < 0) {

perhaps you can use here kmemdup() ?

re,
 wh