From: Juergen Kreileder <jk@blackdown.de>
Date: Tue, 21 Feb 2006 02:28:00 +0000 (-0800)
Subject: [PATCH] Fix snd-usb-audio in 32-bit compat environment
X-Git-Tag: v2.6.16-rc5~93
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aa657ca9245a06fa435e00332a13da1fce182abc;p=linux-2.6

[PATCH] Fix snd-usb-audio in 32-bit compat environment

I'm getting oopses with snd-usb-audio in 32-bit compat environments:
control_compat.c:get_ctl_type() doesn't initialize 'info', so
'itemlist[uinfo->value.enumerated.item]' in
usbmixer.c:mixer_ctl_selector_info() might access random memory (The 'if
((int)uinfo->value.enumerated.item >= cval->max)' doesn't fix all problems
because of the unsigned -> signed conversion.)

Signed-off-by: Juergen Kreileder <jk@blackdown.de>
Cc: Jaroslav Kysela <perex@suse.cz>
Acked-by: Takashi Iwai <tiwai@suse.de>
Cc: Greg KH <greg@kroah.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/sound/core/control_compat.c b/sound/core/control_compat.c
index 418c6d4e5d..a529b62972 100644
--- a/sound/core/control_compat.c
+++ b/sound/core/control_compat.c
@@ -167,7 +167,7 @@ static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
 			int *countp)
 {
 	struct snd_kcontrol *kctl;
-	struct snd_ctl_elem_info info;
+	struct snd_ctl_elem_info *info;
 	int err;
 
 	down_read(&card->controls_rwsem);
@@ -176,13 +176,19 @@ static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
 		up_read(&card->controls_rwsem);
 		return -ENXIO;
 	}
-	info.id = *id;
-	err = kctl->info(kctl, &info);
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info == NULL) {
+		up_read(&card->controls_rwsem);
+		return -ENOMEM;
+	}
+	info->id = *id;
+	err = kctl->info(kctl, info);
 	up_read(&card->controls_rwsem);
 	if (err >= 0) {
-		err = info.type;
-		*countp = info.count;
+		err = info->type;
+		*countp = info->count;
 	}
+	kfree(info);
 	return err;
 }