From patchwork Fri Dec 11 04:26:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zhu Yanjun X-Patchwork-Id: 342695 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00, DATE_IN_FUTURE_12_24, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FF93C4361B for ; Thu, 10 Dec 2020 07:03:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1AC222D5B for ; Thu, 10 Dec 2020 07:03:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387757AbgLJHC4 (ORCPT ); Thu, 10 Dec 2020 02:02:56 -0500 Received: from mga02.intel.com ([134.134.136.20]:62298 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730039AbgLJHCn (ORCPT ); Thu, 10 Dec 2020 02:02:43 -0500 IronPort-SDR: huzRDa0wOCzOplFyX6Eflwf1dfQNKtQZ4Bo2pV5gYg54fg/Y4f+CN6oLKjXWYs0qOQBCEEf3IM /NElaC/igY+g== X-IronPort-AV: E=McAfee;i="6000,8403,9830"; a="161258205" X-IronPort-AV: E=Sophos;i="5.78,407,1599548400"; d="scan'208";a="161258205" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2020 23:02:20 -0800 IronPort-SDR: aNChuEw80pHWnwSbfDCPRNe/E5BtThRYwKLQ39drUC9NUGH1fEHRtqqHBQeXxg/tFiyebfylLI CzFQJWqISTkA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,407,1599548400"; d="scan'208";a="438230442" Received: from unknown (HELO localhost.localdomain.bj.intel.com) ([10.238.154.69]) by fmsmga001.fm.intel.com with ESMTP; 09 Dec 2020 23:02:18 -0800 From: Zhu Yanjun To: zyjzyj2000@gmail.com, bjorn.topel@intel.com, magnus.karlsson@intel.com, netdev@vger.kernel.org, jonathan.lemon@gmail.com Cc: Zhu Yanjun , Ye Dong Subject: [PATCH v3 1/1] xdp: avoid calling kfree twice Date: Thu, 10 Dec 2020 23:26:10 -0500 Message-Id: <20201211042610.71081-1-yanjun.zhu@intel.com> X-Mailer: git-send-email 2.18.4 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org In the function xdp_umem_pin_pages, if npgs != umem->npgs and npgs >= 0, the function xdp_umem_unpin_pages is called. In this function, kfree is called to handle umem->pgs, and then in the function xdp_umem_pin_pages, kfree is called again to handle umem->pgs. Eventually, to umem->pgs, kfree is called twice. Since umem->pgs is set to NULL after the first kfree, the second kfree would not trigger call trace. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") CC: Ye Dong Acked-by: Björn Töpel Signed-off-by: Zhu Yanjun --- net/xdp/xdp_umem.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 56a28a686988..01b31c56cead 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -97,7 +97,6 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address) { unsigned int gup_flags = FOLL_WRITE; long npgs; - int err; umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs), GFP_KERNEL | __GFP_NOWARN); @@ -112,20 +111,14 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address) if (npgs != umem->npgs) { if (npgs >= 0) { umem->npgs = npgs; - err = -ENOMEM; - goto out_pin; + xdp_umem_unpin_pages(umem); + return -ENOMEM; } - err = npgs; - goto out_pgs; + kfree(umem->pgs); + umem->pgs = NULL; + return (int)npgs; } return 0; - -out_pin: - xdp_umem_unpin_pages(umem); -out_pgs: - kfree(umem->pgs); - umem->pgs = NULL; - return err; } static int xdp_umem_account_pages(struct xdp_umem *umem)