From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:52061 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbeKCEJt (ORCPT ); Sat, 3 Nov 2018 00:09:49 -0400 From: Colin King To: Maxime Ripard , Paul Kocialkowski , Mauro Carvalho Chehab , Greg Kroah-Hartman , Chen-Yu Tsai , linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-arm-kernel@lists.infradead.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][staging-next] drivers: staging: cedrus: find ctx before dereferencing it ctx Date: Fri, 2 Nov 2018 19:01:26 +0000 Message-Id: <20181102190126.5628-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: From: Colin Ian King Currently if count is an invalid value the v4l2_info message will dereference a null ctx pointer to get the dev information. Fix this by finding ctx first and then checking for an invalid count, this way ctxt will be non-null hence avoiding the null pointer dereference. Detected by CoverityScan, CID#1475337 ("Explicit null dereferenced") Fixes: 50e761516f2b ("media: platform: Add Cedrus VPU decoder driver") Signed-off-by: Colin Ian King --- drivers/staging/media/sunxi/cedrus/cedrus.c | 22 ++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c index 82558455384a..699d62dceb6c 100644 --- a/drivers/staging/media/sunxi/cedrus/cedrus.c +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c @@ -108,17 +108,6 @@ static int cedrus_request_validate(struct media_request *req) unsigned int count; unsigned int i; - count = vb2_request_buffer_cnt(req); - if (!count) { - v4l2_info(&ctx->dev->v4l2_dev, - "No buffer was provided with the request\n"); - return -ENOENT; - } else if (count > 1) { - v4l2_info(&ctx->dev->v4l2_dev, - "More than one buffer was provided with the request\n"); - return -EINVAL; - } - list_for_each_entry(obj, &req->objects, list) { struct vb2_buffer *vb; @@ -133,6 +122,17 @@ static int cedrus_request_validate(struct media_request *req) if (!ctx) return -ENOENT; + count = vb2_request_buffer_cnt(req); + if (!count) { + v4l2_info(&ctx->dev->v4l2_dev, + "No buffer was provided with the request\n"); + return -ENOENT; + } else if (count > 1) { + v4l2_info(&ctx->dev->v4l2_dev, + "More than one buffer was provided with the request\n"); + return -EINVAL; + } + parent_hdl = &ctx->hdl; hdl = v4l2_ctrl_request_hdl_find(req, parent_hdl); -- 2.19.1