[PATCH] sound: soc-pcm: add a check to avoid NULL pointer dereference

[Kangjie Lu]

In case debugfs_create_u32 fails, the fix frees memory and returns
an error to notify callers.

Signed-off-by: Kangjie Lu <k...@umn.edu>
---
 sound/soc/soc-pcm.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index 0d5ec68a1e50..a7d88ed8ebb5 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1231,15 +1231,21 @@ static int dpcm_be_connect(struct snd_soc_pcm_runtime 
*fe,
        list_add(&dpcm->list_be, &fe->dpcm[stream].be_clients);
        list_add(&dpcm->list_fe, &be->dpcm[stream].fe_clients);
 
-       dev_dbg(fe->dev, "connected new DPCM %s path %s %s %s\n",
-                       stream ? "capture" : "playback",  fe->dai_link->name,
-                       stream ? "<-" : "->", be->dai_link->name);
-
 #ifdef CONFIG_DEBUG_FS
-       if (fe->debugfs_dpcm_root)
+       if (fe->debugfs_dpcm_root) {
                dpcm->debugfs_state = debugfs_create_u32(be->dai_link->name, 
0644,
                                fe->debugfs_dpcm_root, &dpcm->state);
+               if (!dpcm->debugfs_state) {
+                       kfree(dpcm);
+                       return -ENOMEM;
+               }
+       }
 #endif
+
+       dev_dbg(fe->dev, "connected new DPCM %s path %s %s %s\n",
+                       stream ? "capture" : "playback",  fe->dai_link->name,
+                       stream ? "<-" : "->", be->dai_link->name);
+
        return 1;
 }
 
-- 
2.17.1