ALSA: pcm: oss: Limit the period size to 16MB

stable inclusion
from stable-v4.19.221
commit 2e54cf6794bf82a54aaefc78da13819aea9cd28a
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S1ZV
CVE: CVE-2021-47509

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2e54cf6794bf82a54aaefc78da13819aea9cd28a



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

commit 8839c8c0 upstream.

Set the practical limit to the period size (the fragment shift in OSS)
instead of a full 31bit; a too large value could lead to the exhaust
of memory as we allocate temporary buffers of the period size, too.

As of this patch, we set to 16MB limit, which should cover all use
cases.

Reported-by:  <syzbot+bb348e9f9a954d42746f@syzkaller.appspotmail.com>
Reported-by: Bixuan Cui <cuibixuan@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1638270978-42412-1-git-send-email-cuibixuan@linux.alibaba.com
Link: https://lore.kernel.org/r/20211201073606.11660-3-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>