ALSA: pcm: oss: Fix negative period/buffer sizes
authorTakashi Iwai <tiwai@suse.de>
Wed, 1 Dec 2021 07:36:04 +0000 (08:36 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Dec 2021 09:16:54 +0000 (10:16 +0100)
commit8af815ab052eaf74addbbfb556d63ce2137c0e1b
tree4fd85a39c96c8a7301bea5573a5276ee4990c67f
parent9cfc42d875eba88080ed268b93d4ff196d34b684
ALSA: pcm: oss: Fix negative period/buffer sizes

commit 9d2479c960875ca1239bcb899f386970c13d9cfe upstream.

The period size calculation in OSS layer may receive a negative value
as an error, but the code there assumes only the positive values and
handle them with size_t.  Due to that, a too big value may be passed
to the lower layers.

This patch changes the code to handle with ssize_t and adds the proper
error checks appropriately.

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/20211201073606.11660-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/core/oss/pcm_oss.c