[PATCH 4.6 170/203] ALSA: echoaudio: Fix memory allocation

Greg Kroah-Hartman
2016-07-25T21:42:05Z

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

commit 9c6795a9b3cbb56a9fbfaf43909c5c22999ba317 upstream.

'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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/echoaudio/echoaudio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/pci/echoaudio/echoaudio.c
+++ b/sound/pci/echoaudio/echoaudio.c
@@ -2200,11 +2200,11 @@ static int snd_echo_resume(struct device
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) {