ALSA: usb-audio: Fix double-free in error paths after snd_usb_add_audio_stream()...
authorVladis Dronov <vdronov@redhat.com>
Thu, 31 Mar 2016 16:05:43 +0000 (12:05 -0400)
committerSasha Levin <sasha.levin@oracle.com>
Mon, 11 Jul 2016 03:06:55 +0000 (23:06 -0400)
commit03e046efdbd3bccaac952553065adb70fb6976aa
treeef83c15bc17108e4b47d0d3d4608cffa0b7707d7
parent00ef5df8687ff1a51660a5d27c202417a69b5018
ALSA: usb-audio: Fix double-free in error paths after snd_usb_add_audio_stream() call

[ Upstream commit 836b34a935abc91e13e63053d0a83b24dfb5ea78 ]

create_fixed_stream_quirk(), snd_usb_parse_audio_interface() and
create_uaxx_quirk() functions allocate the audioformat object by themselves
and free it upon error before returning. However, once the object is linked
to a stream, it's freed again in snd_usb_audio_pcm_free(), thus it'll be
double-freed, eventually resulting in a memory corruption.

This patch fixes these failures in the error paths by unlinking the audioformat
object before freeing it.

Based on a patch by Takashi Iwai <tiwai@suse.de>

[Note for stable backports:
 this patch requires the commit 902eb7fd1e4a ('ALSA: usb-audio: Minor
 code cleanup in create_fixed_stream_quirk()')]

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1283358
Reported-by: Ralf Spenneberg <ralf@spenneberg.net>
Cc: <stable@vger.kernel.org> # see the note above
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
sound/usb/quirks.c
sound/usb/stream.c