From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DCFFC433F5 for ; Tue, 9 Nov 2021 22:40:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C2B260FDA for ; Tue, 9 Nov 2021 22:40:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344870AbhKIWmn (ORCPT ); Tue, 9 Nov 2021 17:42:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:60124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345367AbhKIWkO (ORCPT ); Tue, 9 Nov 2021 17:40:14 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E035761B1C; Tue, 9 Nov 2021 22:23:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636496621; bh=tYjtW025gHLRr8426PhlfQYECjhcjlWc5ctzxhuJJ2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ponmLuvQfoM/ZCSHDR5SWTq++XUmF8J2JLlLuTT/UDH+qzqYYy73USl3pvMp4NcUG eVyOQdCohmLYfiVoR/VDFdEXfO9kVVJNyvhxBZJD395io4bs/orF3G9znIsnV8XsbX BplBcDSh9Y5ICiaB7QZX5mr+QbSfC6xeHaGqPWrxPW7bySzn7/acXrew+ZYNLS+piv tq2mf709gD6uLaC5XfccGq1+UGRBY4dnEuxXg8jzrApO81rM79Tu0rYLMSad24+6SW WRIcozFY2v/pylh7s7iZ9tnOR9F8uKD9+bftsXALOXiUj0CBo3NrdEKRtzl4aJwC7i uVKA5jVssC6fg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chengfeng Ye , Takashi Iwai , Sasha Levin , perex@perex.cz, tiwai@suse.com, alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.19 20/21] ALSA: gus: fix null pointer dereference on pointer block Date: Tue, 9 Nov 2021 17:23:09 -0500 Message-Id: <20211109222311.1235686-20-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109222311.1235686-1-sashal@kernel.org> References: <20211109222311.1235686-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chengfeng Ye [ Upstream commit a0d21bb3279476c777434c40d969ea88ca64f9aa ] The pointer block return from snd_gf1_dma_next_block could be null, so there is a potential null pointer dereference issue. Fix this by adding a null check before dereference. Signed-off-by: Chengfeng Ye Link: https://lore.kernel.org/r/20211024104611.9919-1-cyeaa@connect.ust.hk Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/isa/gus/gus_dma.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/isa/gus/gus_dma.c b/sound/isa/gus/gus_dma.c index 7f95f452f1064..48e76b8fede41 100644 --- a/sound/isa/gus/gus_dma.c +++ b/sound/isa/gus/gus_dma.c @@ -141,6 +141,8 @@ static void snd_gf1_dma_interrupt(struct snd_gus_card * gus) } block = snd_gf1_dma_next_block(gus); spin_unlock(&gus->dma_lock); + if (!block) + return; snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd); kfree(block); #if 0 -- 2.33.0