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 AD265C5DF62 for ; Wed, 26 Jan 2022 00:40:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235390AbiAZAkF (ORCPT ); Tue, 25 Jan 2022 19:40:05 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:43758 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235377AbiAZAkC (ORCPT ); Tue, 25 Jan 2022 19:40:02 -0500 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9DD9A71; Wed, 26 Jan 2022 01:40:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1643157600; bh=39YQOO8kiCwng87xf7Zi6eCskEERmKQqrn0Nu4BVpXo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r5GW3Mw0xK410gpYL/hg5EKhG13Pk5J9eQsuwXEGGwu3iWTpk5ztm3RaWKR5iJWK+ Ul7h8kQgjTaHfgRMYLCqTgvEckdp7PU/9Nnu4/eHfhuqjILkkBrj1L6NWqvLVDk/r5 ssOGzA/8uQYPMtpDmnMFlTcxOtyabQXxEac5qMVM= Date: Wed, 26 Jan 2022 02:39:41 +0200 From: Laurent Pinchart To: Zhou Qingyang Cc: kjlu@umn.edu, Benoit Parrot , Mauro Carvalho Chehab , Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] media: ti-vpe: cal: Fix a NULL pointer dereference in cal_ctx_v4l2_init_formats() Message-ID: References: <20220124172001.62457-1-zhou1615@umn.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220124172001.62457-1-zhou1615@umn.edu> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Zhou, Thank you for the patch. On Tue, Jan 25, 2022 at 01:20:01AM +0800, Zhou Qingyang wrote: > In cal_ctx_v4l2_init_formats(), devm_kzalloc() is assigned to fw and there What do you mean by "fw" here ? It could be replaced with "is assigned to ctx->active_fmt". If you're fine with this change, there's no need to resend, I can fix this when applying. > is a dereference of it after that, which could lead to NULL pointer > dereference on failure of devm_kzalloc(). > > Fix this bug by adding a NULL check of ctx->active_fmt. > > This bug was found by a static analyzer. > > Builds with 'make allyesconfig' show no new warnings, > and our static analyzer no longer warns about this code. > > Fixes: 7168155002cf ("media: ti-vpe: cal: Move format handling to cal.c and expose helpers") > Signed-off-by: Zhou Qingyang Reviewed-by: Laurent Pinchart > -- > The analysis employs differential checking to identify inconsistent > security operations (e.g., checks or kfrees) between two code paths > and confirms that the inconsistent operations are not recovered in the > current function or the callers, so they constitute bugs. > > Note that, as a bug found by static analysis, it can be a false > positive or hard to trigger. Multiple researchers have cross-reviewed > the bug. > > drivers/media/platform/ti-vpe/cal-video.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/media/platform/ti-vpe/cal-video.c b/drivers/media/platform/ti-vpe/cal-video.c > index 7799da1cc261..3e936a2ca36c 100644 > --- a/drivers/media/platform/ti-vpe/cal-video.c > +++ b/drivers/media/platform/ti-vpe/cal-video.c > @@ -823,6 +823,9 @@ static int cal_ctx_v4l2_init_formats(struct cal_ctx *ctx) > /* Enumerate sub device formats and enable all matching local formats */ > ctx->active_fmt = devm_kcalloc(ctx->cal->dev, cal_num_formats, > sizeof(*ctx->active_fmt), GFP_KERNEL); > + if (!ctx->active_fmt) > + return -ENOMEM; > + > ctx->num_active_fmt = 0; > > for (j = 0, i = 0; ; ++j) { -- Regards, Laurent Pinchart