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 C9E05C433F5 for ; Tue, 9 Nov 2021 22:37:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2EC260FED for ; Tue, 9 Nov 2021 22:37:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345432AbhKIWkh (ORCPT ); Tue, 9 Nov 2021 17:40:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:58692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344462AbhKIWiM (ORCPT ); Tue, 9 Nov 2021 17:38:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D45E661AFE; Tue, 9 Nov 2021 22:23:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636496588; bh=KFya8t7XucbD4ytnXfZ1+zfqS0YsfWJVp8FuMTEXMeU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=svj0Yn8Bb75tJmRODhxIWgEX8vSBU4cWeevHrjGuxxHyAwM6Q/tfovAdwap6zfCT+ 5JkFM9in2FHG/7gaTh8g34fUN+bwtgicFNHdqfDr4U/VFA5VE6dro1eajylejs1Tj5 +HcRZlVGsKgopfg0gC8AcjXq6s/9koNLwl23kx0s4UIPtVzq0lak8wteMjDk+z2yPx ATkv0mMdC2CoQW2VJ89AcuI0VrmTTiupSOE5Yd/SXl4iI+ZhDLRPh6jocGQyX7nn2i b3qxaDIePmDzgAtRppNg4cLJ4o+NuHU6cD/awtibOhnYK+aspjvTOQXp7knsTyXPuD kPL543KEci5oA== 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 5.4 29/30] ALSA: gus: fix null pointer dereference on pointer block Date: Tue, 9 Nov 2021 17:22:23 -0500 Message-Id: <20211109222224.1235388-29-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109222224.1235388-1-sashal@kernel.org> References: <20211109222224.1235388-1-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 a1c770d826dda..6d664dd8dde0b 100644 --- a/sound/isa/gus/gus_dma.c +++ b/sound/isa/gus/gus_dma.c @@ -126,6 +126,8 @@ 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