From: Florin Malita <fmalita@gmail.com>
Date: Fri, 29 Sep 2006 10:55:25 +0000 (+0200)
Subject: [ALSA] Dereference after free in snd_hwdep_release()
X-Git-Tag: v2.6.19-rc2~286^2~6
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=104326f8df9925317cca64b84249d3eac5de7c74;p=linux-2.6

[ALSA] Dereference after free in snd_hwdep_release()

snd_card_file_remove() may free hw->card so we can't dereference
hw->card->module after that.
Coverity ID 1420.

Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
---

diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index 9aa9d94891..46b4768936 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -158,6 +158,7 @@ static int snd_hwdep_release(struct inode *inode, struct file * file)
 {
 	int err = -ENXIO;
 	struct snd_hwdep *hw = file->private_data;
+	struct module *mod = hw->card->module;
 	mutex_lock(&hw->open_mutex);
 	if (hw->ops.release) {
 		err = hw->ops.release(hw, file);
@@ -167,7 +168,7 @@ static int snd_hwdep_release(struct inode *inode, struct file * file)
 		hw->used--;
 	snd_card_file_remove(hw->card, file);
 	mutex_unlock(&hw->open_mutex);
-	module_put(hw->card->module);
+	module_put(mod);
 	return err;
 }