ALSA: rawmidi - Fix possible race in open

The module refcount should be handled in the register_mutex to avoid
possible races with module unloading.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 7 insertions, 7 deletions

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 002777ba336a..60f33e9412ad 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -237,15 +237,16 @@ int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
                 rfile->input = rfile->output = NULL;
         mutex_lock(&register_mutex);
         rmidi = snd_rawmidi_search(card, device);
-        mutex_unlock(&register_mutex);
         if (rmidi == NULL) {
-                err = -ENODEV;
-                goto __error1;
+                mutex_unlock(&register_mutex);
+                return -ENODEV;
         }
         if (!try_module_get(rmidi->card->module)) {
-                err = -EFAULT;
-                goto __error1;
+                mutex_unlock(&register_mutex);
+                return -ENXIO;
         }
+        mutex_unlock(&register_mutex);
+
         if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
                 mutex_lock(&rmidi->open_mutex);
         if (mode & SNDRV_RAWMIDI_LFLG_INPUT) {
@@ -370,10 +371,9 @@ int snd_rawmidi_kernel_open(struct snd_card *card, int device, int subdevice,
                 snd_rawmidi_runtime_free(sinput);
         if (output != NULL)
                 snd_rawmidi_runtime_free(soutput);
-        module_put(rmidi->card->module);
         if (!(mode & SNDRV_RAWMIDI_LFLG_NOOPENLOCK))
                 mutex_unlock(&rmidi->open_mutex);
-      __error1:
+        module_put(rmidi->card->module);
         return err;
 }