From patchwork Mon Dec 13 09:30:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 524124 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70B94C433F5 for ; Mon, 13 Dec 2021 09:45:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235920AbhLMJpd (ORCPT ); Mon, 13 Dec 2021 04:45:33 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:36804 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233053AbhLMJnT (ORCPT ); Mon, 13 Dec 2021 04:43:19 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id E8FCECE0E6F; Mon, 13 Dec 2021 09:43:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B4FC341CA; Mon, 13 Dec 2021 09:43:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1639388596; bh=rinA5Oho5YlhS85gOrLe4tXmrUm1hPkE6VJnbLkHfXE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TXUDuPR22YAKd4QRIXhbs+QpAL5IJOKX0noLQ9BEfax2lE92zuYCmvTk6QoL4m0vg aqPPfUMR29MMlEKqu0I+JVyayx0DVCXZQyKWL4ydJlehXYU5yHYc9LkKcSWPe2FgnN PFphlIXrJ/VlP0uRoiYFhph1oh7N/ZwIp0XJERHQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+bb348e9f9a954d42746f@syzkaller.appspotmail.com, Bixuan Cui , Takashi Iwai Subject: [PATCH 5.4 31/88] ALSA: pcm: oss: Limit the period size to 16MB Date: Mon, 13 Dec 2021 10:30:01 +0100 Message-Id: <20211213092934.298941420@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211213092933.250314515@linuxfoundation.org> References: <20211213092933.250314515@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit 8839c8c0f77ab8fc0463f4ab8b37fca3f70677c2 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 Cc: 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 Signed-off-by: Greg Kroah-Hartman --- sound/core/oss/pcm_oss.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1952,7 +1952,7 @@ static int snd_pcm_oss_set_fragment1(str if (runtime->oss.subdivision || runtime->oss.fragshift) return -EINVAL; fragshift = val & 0xffff; - if (fragshift >= 31) + if (fragshift >= 25) /* should be large enough */ return -EINVAL; runtime->oss.fragshift = fragshift; runtime->oss.maxfrags = (val >> 16) & 0xffff;