[PATCH 3.16 002/148] ALSA: line6: Fix memory leak at line6_init_pcm() error path

From: Ben Hutchings
Date: Sat Feb 08 2020 - 13:29:45 EST


3.16.82-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Takashi Iwai <tiwai@xxxxxxx>

commit 1bc8d18c75fef3b478dbdfef722aae09e2a9fde7 upstream.

I forgot to release the allocated object at the early error path in
line6_init_pcm(). For addressing it, slightly shuffle the code so
that the PCM destructor (pcm->private_free) is assigned properly
before all error paths.

Fixes: 3450121997ce ("ALSA: line6: Fix write on zero-sized buffer")
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/staging/line6/pcm.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/drivers/staging/line6/pcm.c
+++ b/drivers/staging/line6/pcm.c
@@ -478,6 +478,15 @@ int line6_init_pcm(struct usb_line6 *lin
line6pcm->ep_audio_read = ep_read;
line6pcm->ep_audio_write = ep_write;

+ spin_lock_init(&line6pcm->lock_audio_out);
+ spin_lock_init(&line6pcm->lock_audio_in);
+ spin_lock_init(&line6pcm->lock_trigger);
+
+ line6->line6pcm = line6pcm;
+
+ pcm->private_data = line6pcm;
+ pcm->private_free = line6_cleanup_pcm;
+
/* Read and write buffers are sized identically, so choose minimum */
line6pcm->max_packet_size = min(
usb_maxpacket(line6->usbdev,
@@ -490,15 +499,6 @@ int line6_init_pcm(struct usb_line6 *lin
return -EINVAL;
}

- spin_lock_init(&line6pcm->lock_audio_out);
- spin_lock_init(&line6pcm->lock_audio_in);
- spin_lock_init(&line6pcm->lock_trigger);
-
- line6->line6pcm = line6pcm;
-
- pcm->private_data = line6pcm;
- pcm->private_free = line6_cleanup_pcm;
-
err = line6_create_audio_out_urbs(line6pcm);
if (err < 0)
return err;