From patchwork Mon May 25 14:15:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiyu Yang X-Patchwork-Id: 11568873 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6E9DB14B7 for ; Mon, 25 May 2020 14:16:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D4CC2087D for ; Mon, 25 May 2020 14:16:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fudan.edu.cn header.i=@fudan.edu.cn header.b="FgVc/37q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388873AbgEYOQV (ORCPT ); Mon, 25 May 2020 10:16:21 -0400 Received: from mail.fudan.edu.cn ([202.120.224.10]:52101 "EHLO fudan.edu.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388714AbgEYOQV (ORCPT ); Mon, 25 May 2020 10:16:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fudan.edu.cn; s=dkim; h=Received:From:To:Cc:Subject:Date: Message-Id; bh=A2C6VJveWD7/k0MVHTpe6FT8HSlUTvfLdgwU7DetgHI=; b=F gVc/37qjCWc81JOyIy9zjfz0hxwLFOMlaceF5MaATZ1PV1RIuf/iNwdCWKLxv/tx gUPvkVzsqsumy3tWQ/SNt/CkHPzibbSIbYsCzmOiRsPXRFKRqAkHOysyJj0u1hzs LSZcZQSxetU8gEfLNJ7PZy0rfd4JkBjRxas+tgTjpM= Received: from localhost.localdomain (unknown [223.73.184.21]) by app1 (Coremail) with SMTP id XAUFCgC3vpoq08tejM8wAg--.42131S3; Mon, 25 May 2020 22:16:11 +0800 (CST) From: Xiyu Yang To: "J. Bruce Fields" , Chuck Lever , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Cc: yuanxzhang@fudan.edu.cn, kjlu@umn.edu, Xiyu Yang , Xin Tan Subject: [PATCH] nfsd: Fix svc_xprt refcnt leak when setup callback client failed Date: Mon, 25 May 2020 22:15:41 +0800 Message-Id: <1590416141-52534-1-git-send-email-xiyuyang19@fudan.edu.cn> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: XAUFCgC3vpoq08tejM8wAg--.42131S3 X-Coremail-Antispam: 1UD129KBjvdXoW7JFW8Kr48uFyUZFWfCryfJFb_yoWDAFX_Gr 4fXr1DX348tF17JFyxtrWvyrW0g3yDGFyUGFWvy343GFWF93yDXF93trnrWF47KrWaqw1a yFyDGr9I9aySvjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbskFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr1j 6rxdM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1Y6r17McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAG YxC7MxkIecxEwVAFwVW5XwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8Jw C20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAF wI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjx v20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6Fyj6rWUJwCI42IY6I8E 87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73Uj IFyTuYvjfUOyCJUUUUU X-CM-SenderInfo: irzsiiysuqikmy6i3vldqovvfxof0/ Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org nfsd4_process_cb_update() invokes svc_xprt_get(), which increases the refcount of the "c->cn_xprt". The reference counting issue happens in one exception handling path of nfsd4_process_cb_update(). When setup callback client failed, the function forgets to decrease the refcnt increased by svc_xprt_get(), causing a refcnt leak. Fix this issue by calling svc_xprt_put() when setup callback client failed. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan --- fs/nfsd/nfs4callback.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index 5cf91322de0f..07e0c6f6322f 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1301,6 +1301,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) err = setup_callback_client(clp, &conn, ses); if (err) { nfsd4_mark_cb_down(clp, err); + if (c) + svc_xprt_put(c->cn_xprt); return; } }