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| author |   Takashi Iwai <tiwai@suse.de> | 2012-10-16 13:05:59 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-10-30 11:07:10 +0100 |
| commit | a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 (patch) | |
| tree | 4dc74b708a07b56d12ed72a34d0a2e0cb8c8b9d4 /sound/core/rawmidi.c | |
| parent | ALSA: usb-audio: Fix races at disconnection in mixer_quirks.c (diff) | |
| download | linux-dev-a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85.tar.xz linux-dev-a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85.zip | |
ALSA: Add a reference counter to card instance
For more strict protection for wild disconnections, a refcount is
introduced to the card instance, and let it up/down when an object is
referred via snd_lookup_*() in the open ops.
The free-after-last-close check is also changed to check this refcount
instead of the empty list, too.
Reported-by: Matthieu CASTET <matthieu.castet@parrot.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/rawmidi.c')
| -rw-r--r-- | sound/core/rawmidi.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index ebf6e49ad3d4..7d4f62ab6711 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -379,8 +379,10 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) if (rmidi == NULL) return -ENODEV; - if (!try_module_get(rmidi->card->module)) + if (!try_module_get(rmidi->card->module)) { + snd_card_unref(rmidi->card); return -ENXIO; + } mutex_lock(&rmidi->open_mutex); card = rmidi->card; @@ -440,6 +442,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) #endif file->private_data = rawmidi_file; mutex_unlock(&rmidi->open_mutex); + snd_card_unref(rmidi->card); return 0; __error: @@ -447,6 +450,7 @@ static int snd_rawmidi_open(struct inode *inode, struct file *file) __error_card: mutex_unlock(&rmidi->open_mutex); module_put(rmidi->card->module); + snd_card_unref(rmidi->card); return err; } |