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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E74CFA3742 for ; Mon, 31 Oct 2022 12:49:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231445AbiJaMsz (ORCPT ); Mon, 31 Oct 2022 08:48:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231281AbiJaMsv (ORCPT ); Mon, 31 Oct 2022 08:48:51 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0EE3EE15; Mon, 31 Oct 2022 05:48:50 -0700 (PDT) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 48DEA6602387; Mon, 31 Oct 2022 12:48:48 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1667220528; bh=ETLcOC6RqGvMLvwInB/+hn555B0YojoNFYRHkoq15ys=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=IVJTu5Kmw6Bx3dBbjqANAxFC42H8FCVyp7y5hDD88QU6z/8dffprYyNN7wg7NfQlL VPdKu/AIXrBedGLMVMl3rUzDrlqCQqD2ZqcwvNUO0UcAiUTm6wZgH7CQaa4Fg+KQUi r1SkLpU5f9hR4yku37q7q8UdrVoV15MFT0mPGwUoM+ReQhPO+Yb8Xxqh/gQ6whADPm zXBQiS24Qsl81Jhx19reqEmL47I7O4vR5T0QqaKuR14Ufy0/VKJ3wWW1kVlaMmgXGR XlKzP9qSY8bWQjxIwh9B3zgiUqYpeWlqLdnFbnqyxS0ML3bvk1kDRl+C02Q7/uOLvP ijCjc4NCnI0iw== Message-ID: <2fbf35b9-3cad-4211-db5b-501d5eb14a2e@collabora.com> Date: Mon, 31 Oct 2022 13:48:45 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.3 Subject: Re: [PATCH] vcodec: mediatek: add check for NULL for vsi->frm_bufs[vsi->new_fb_idx].buf.fb in vp9_swap_frm_bufs Content-Language: en-US To: Nicolas Dufresne , Anastasia Belova , Mauro Carvalho Chehab , Matthias Brugger Cc: Tiffany Lin , Andrew-CT Chen , Yunfei Dong , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, lvc-project@linuxtesting.org References: <20221028125811.11340-1-abelova@astralinux.ru> <664bd195bdde7fd740572c4981c60b32de1465aa.camel@collabora.com> From: AngeloGioacchino Del Regno In-Reply-To: <664bd195bdde7fd740572c4981c60b32de1465aa.camel@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 28/10/22 15:02, Nicolas Dufresne ha scritto: > Hi, > > Le vendredi 28 octobre 2022 à 15:58 +0300, Anastasia Belova a écrit : >> If vsi->frm_bufs[vsi->new_fb_idx].buf.fb == NULL while cleaning >> fb_free_list NULL-pointer is dereferenced. >> >> Found by Linux Verification Center (linuxtesting.org) with SVACE. >> >> Fixes: f77e89854b3e ("[media] vcodec: mediatek: Add Mediatek VP9 Video Decoder Driver") >> >> Signed-off-by: Anastasia Belova >> --- >> drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_if.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_if.c b/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_if.c >> index 70b8383f7c8e..b0679aaf6192 100644 >> --- a/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_if.c >> +++ b/drivers/media/platform/mediatek/vcodec/vdec/vdec_vp9_if.c >> @@ -512,7 +512,7 @@ static void vp9_swap_frm_bufs(struct vdec_vp9_inst *inst) >> * clean fb_free_list >> */ >> if (vsi->frm_bufs[vsi->new_fb_idx].ref_cnt == 0) { >> - if (!vp9_is_sf_ref_fb( >> + if (vsi->frm_bufs[vsi->new_fb_idx].buf.fb != NULL && !vp9_is_sf_ref_fb( >> inst, vsi->frm_bufs[vsi->new_fb_idx].buf.fb)) { >> struct vdec_fb *fb; > > Perhaps we could try and maintain some readability ? I'd suggest to move the > check into vp9_is_sf_ref_fb() as an early return. > I don't think that this will ever happen, as the check was omitted because of being totally sure that vsi->frm_bufs[vsi->new_fb_idx].buf.fb is not NULL. In any case, it doesn't really cost anything to add a check... in which case, I agree with Nicolas about moving that to vp9_is_sf_ref_fb(). if (!fb) return false for ..... Regards, Angelo