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{
    "id": 11547,
    "url": "https://patchwork.libcamera.org/api/1.1/patches/11547/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/11547/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20210311093325.8933-1-m.cichy@pengutronix.de>",
    "date": "2021-03-11T09:33:25",
    "name": "[libcamera-devel,v2] libcamera: gst: Fix double-free when acquire_buffer fails",
    "commit_ref": null,
    "pull_url": null,
    "state": "accepted",
    "archived": false,
    "hash": "2a231a6ad34fc2ae7a83aaa28c1ceaea53bc0203",
    "submitter": {
        "id": 80,
        "url": "https://patchwork.libcamera.org/api/1.1/people/80/?format=api",
        "name": "Marian Cichy",
        "email": "m.cichy@pengutronix.de"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/11547/mbox/",
    "series": [
        {
            "id": 1783,
            "url": "https://patchwork.libcamera.org/api/1.1/series/1783/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=1783",
            "date": "2021-03-11T09:33:25",
            "name": "[libcamera-devel,v2] libcamera: gst: Fix double-free when acquire_buffer fails",
            "version": 2,
            "mbox": "https://patchwork.libcamera.org/series/1783/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/11547/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/11547/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>",
        "X-Original-To": "parsemail@patchwork.libcamera.org",
        "Delivered-To": "parsemail@patchwork.libcamera.org",
        "Received": [
            "from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id B4FC4BD1F1\n\tfor <parsemail@patchwork.libcamera.org>;\n\tThu, 11 Mar 2021 09:33:39 +0000 (UTC)",
            "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id E1E9568C69;\n\tThu, 11 Mar 2021 10:33:38 +0100 (CET)",
            "from metis.ext.pengutronix.de (metis.ext.pengutronix.de\n\t[IPv6:2001:67c:670:201:290:27ff:fe1d:cc33])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 063C868AA3\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 11 Mar 2021 10:33:37 +0100 (CET)",
            "from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28])\n\tby metis.ext.pengutronix.de with esmtps\n\t(TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92)\n\t(envelope-from <mci@pengutronix.de>)\n\tid 1lKHhI-00067z-Bm; Thu, 11 Mar 2021 10:33:36 +0100",
            "from mci by dude02.hi.pengutronix.de with local (Exim 4.92)\n\t(envelope-from <mci@pengutronix.de>)\n\tid 1lKHhH-0002Ll-Ug; Thu, 11 Mar 2021 10:33:35 +0100"
        ],
        "From": "Marian Cichy <m.cichy@pengutronix.de>",
        "To": "libcamera-devel@lists.libcamera.org",
        "Date": "Thu, 11 Mar 2021 10:33:25 +0100",
        "Message-Id": "<20210311093325.8933-1-m.cichy@pengutronix.de>",
        "X-Mailer": "git-send-email 2.29.2",
        "MIME-Version": "1.0",
        "X-SA-Exim-Connect-IP": "2001:67c:670:100:1d::28",
        "X-SA-Exim-Mail-From": "mci@pengutronix.de",
        "X-SA-Exim-Scanned": "No (on metis.ext.pengutronix.de);\n\tSAEximRunCond expanded to false",
        "X-PTX-Original-Recipient": "libcamera-devel@lists.libcamera.org",
        "Subject": "[libcamera-devel] [PATCH v2] libcamera: gst: Fix double-free when\n\tacquire_buffer fails",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "Cc": "graphics@pengutronix.de, Marian Cichy <m.cichy@pengutronix.de>",
        "Content-Type": "text/plain; charset=\"us-ascii\"",
        "Content-Transfer-Encoding": "7bit",
        "Errors-To": "libcamera-devel-bounces@lists.libcamera.org",
        "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"
    },
    "content": "If gst_buffer_pool_acquire_buffer in gst_libcamera_task_run fails, the\nunique_ptr to the request-object gets reset and hence, its destructor\nis called. However, the wrap-object points to the same object and is\nstill alive at this moment. When the task_run-function is finished, the\ndestructor of the wrap-object is called, which in return calls the\ndestructor of the request-object again.\n\nInstead of taking care of both, the request and the wrap-object, we can\nmove the request to the wrap which will then effectively take care of\nthe request object automatically.\n\nSigned-off-by: Marian Cichy <m.cichy@pengutronix.de>\nSuggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>\n---\n src/gstreamer/gstlibcamerasrc.cpp | 28 ++++++++++++----------------\n 1 file changed, 12 insertions(+), 16 deletions(-)",
    "diff": "diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp\nindex 636c14df..e86c3d7f 100644\n--- a/src/gstreamer/gstlibcamerasrc.cpp\n+++ b/src/gstreamer/gstlibcamerasrc.cpp\n@@ -52,19 +52,19 @@ GST_DEBUG_CATEGORY_STATIC(source_debug);\n #define GST_CAT_DEFAULT source_debug\n \n struct RequestWrap {\n-\tRequestWrap(Request *request);\n+\tRequestWrap(std::unique_ptr<Request> request);\n \t~RequestWrap();\n \n \tvoid attachBuffer(GstBuffer *buffer);\n \tGstBuffer *detachBuffer(Stream *stream);\n \n \t/* For ptr comparison only. */\n-\tRequest *request_;\n+\tstd::unique_ptr<Request> request_;\n \tstd::map<Stream *, GstBuffer *> buffers_;\n };\n \n-RequestWrap::RequestWrap(Request *request)\n-\t: request_(request)\n+RequestWrap::RequestWrap(std::unique_ptr<Request> request)\n+\t: request_(std::move(request))\n {\n }\n \n@@ -74,8 +74,6 @@ RequestWrap::~RequestWrap()\n \t\tif (item.second)\n \t\t\tgst_buffer_unref(item.second);\n \t}\n-\n-\tdelete request_;\n }\n \n void RequestWrap::attachBuffer(GstBuffer *buffer)\n@@ -164,7 +162,7 @@ GstLibcameraSrcState::requestCompleted(Request *request)\n \tstd::unique_ptr<RequestWrap> wrap = std::move(requests_.front());\n \trequests_.pop();\n \n-\tg_return_if_fail(wrap->request_ == request);\n+\tg_return_if_fail(wrap->request_.get() == request);\n \n \tif ((request->status() == Request::RequestCancelled)) {\n \t\tGST_DEBUG_OBJECT(src_, \"Request was cancelled\");\n@@ -268,8 +266,7 @@ gst_libcamera_src_task_run(gpointer user_data)\n \tGstLibcameraSrc *self = GST_LIBCAMERA_SRC(user_data);\n \tGstLibcameraSrcState *state = self->state;\n \n-\tstd::unique_ptr<Request> request = state->cam_->createRequest();\n-\tauto wrap = std::make_unique<RequestWrap>(request.get());\n+\tauto wrap = std::make_unique<RequestWrap>(state->cam_->createRequest());\n \tfor (GstPad *srcpad : state->srcpads_) {\n \t\tGstLibcameraPool *pool = gst_libcamera_pad_get_pool(srcpad);\n \t\tGstBuffer *buffer;\n@@ -279,24 +276,23 @@ gst_libcamera_src_task_run(gpointer user_data)\n \t\t\t\t\t\t     &buffer, nullptr);\n \t\tif (ret != GST_FLOW_OK) {\n \t\t\t/*\n-\t\t\t * RequestWrap does not take ownership, and we won't be\n-\t\t\t * queueing this one due to lack of buffers.\n+\t\t\t * RequestWrap has ownership of the rquest, and we\n+\t\t\t * won't be queueing this one due to lack of buffers.\n \t\t\t */\n-\t\t\trequest.reset();\n+\t\t\twrap.release();\n \t\t\tbreak;\n \t\t}\n \n \t\twrap->attachBuffer(buffer);\n \t}\n \n-\tif (request) {\n+\tif (wrap) {\n \t\tGLibLocker lock(GST_OBJECT(self));\n \t\tGST_TRACE_OBJECT(self, \"Requesting buffers\");\n-\t\tstate->cam_->queueRequest(request.get());\n+\t\tstate->cam_->queueRequest(wrap->request_.get());\n \t\tstate->requests_.push(std::move(wrap));\n \n-\t\t/* The request will be deleted in the completion handler. */\n-\t\trequest.release();\n+\t\t/* The RequestWrap will be deleted in the completion handler. */\n \t}\n \n \tGstFlowReturn ret = GST_FLOW_OK;\n",
    "prefixes": [
        "libcamera-devel",
        "v2"
    ]
}