ALSA: Fix yet another race in disconnection
This patch fixes a race between snd_card_file_remove() and
snd_card_disconnect(). When the card is added to shutdown_files list
in snd_card_disconnect(), but it's freed in snd_card_file_remove() at
the same time, the shutdown_files list gets corrupted. The list member
must be freed in snd_card_file_remove() as well.
Reported-and-tested-by: Russ Dill <russ.dill@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/init.c b/sound/core/init.c
index 3e65da2..a0080aa 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -848,6 +848,7 @@
return -ENOMEM;
mfile->file = file;
mfile->disconnected_f_op = NULL;
+ INIT_LIST_HEAD(&mfile->shutdown_list);
spin_lock(&card->files_lock);
if (card->shutdown) {
spin_unlock(&card->files_lock);
@@ -883,6 +884,9 @@
list_for_each_entry(mfile, &card->files_list, list) {
if (mfile->file == file) {
list_del(&mfile->list);
+ spin_lock(&shutdown_lock);
+ list_del(&mfile->shutdown_list);
+ spin_unlock(&shutdown_lock);
if (mfile->disconnected_f_op)
fops_put(mfile->disconnected_f_op);
found = mfile;