ALSA: echoaudio: Fix memory allocation

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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/sound/pci/echoaudio/echoaudio.c b/sound/pci/echoaudio/echoaudio.c
index 9fd694c..69e78ce 100644 (file)
--- a/sound/pci/echoaudio/echoaudio.c
+++ b/sound/pci/echoaudio/echoaudio.c
@@ -2251,11 +2251,11 @@ static int snd_echo_resume(struct pci_dev *pci)
 
        DE_INIT(("resume start\n"));
        pci_restore_state(pci);
-       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) {