-stable review patch. If anyone has any objections, please let us know.
------------------
From: Florin Malita <[email protected]>
[PATCH] 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.
This bug actually causes an Oops at usb-disconnection, especially
with CONFIG_PREEMPT.
From: Florin Malita <[email protected]>
Signed-off-by: Florin Malita <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
sound/core/hwdep.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- linux-2.6.18.1.orig/sound/core/hwdep.c
+++ linux-2.6.18.1/sound/core/hwdep.c
@@ -158,6 +158,7 @@ static int snd_hwdep_release(struct inod
{
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 inod
hw->used--;
snd_card_file_remove(hw->card, file);
mutex_unlock(&hw->open_mutex);
- module_put(hw->card->module);
+ module_put(mod);
return err;
}
--