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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 597C9C4360F for ; Mon, 18 Mar 2019 17:00:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3574E205F4 for ; Mon, 18 Mar 2019 17:00:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727540AbfCRRAg (ORCPT ); Mon, 18 Mar 2019 13:00:36 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:37872 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727142AbfCRRAf (ORCPT ); Mon, 18 Mar 2019 13:00:35 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4B3F01650; Mon, 18 Mar 2019 10:00:35 -0700 (PDT) Received: from arrakis.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E7E473F614; Mon, 18 Mar 2019 10:00:33 -0700 (PDT) From: Catalin Marinas To: linux-nfs@vger.kernel.org Cc: linux-kernel@vger.kernel.org, trond.myklebust@hammerspace.com, anna.schumaker@netapp.com, stable@vger.kernel.org, NeilBrown Subject: [PATCH] NFS: Fix nfs4_lock_state refcounting in nfs4_alloc_{lock,unlock}data() Date: Mon, 18 Mar 2019 17:00:28 +0000 Message-Id: <20190318170028.61423-1-catalin.marinas@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Commit 7b587e1a5a6c ("NFS: use locks_copy_lock() to copy locks.") changed the lock copying from memcpy() to the dedicated locks_copy_lock() function. The latter correctly increments the nfs4_lock_state.ls_count via nfs4_fl_copy_lock(), however, this refcount has already been incremented in the nfs4_alloc_{lock,unlock}data(). Kmemleak subsequently reports an unreferenced nfs4_lock_state object as below (arm64 platform): unreferenced object 0xffff8000fce0b000 (size 256): comm "systemd-sysuser", pid 1608, jiffies 4294892825 (age 32.348s) hex dump (first 32 bytes): 20 57 4c fb 00 80 ff ff 20 57 4c fb 00 80 ff ff WL..... WL..... 00 57 4c fb 00 80 ff ff 01 00 00 00 00 00 00 00 .WL............. backtrace: [<000000000d15010d>] kmem_cache_alloc+0x178/0x208 [<00000000d7c1d264>] nfs4_set_lock_state+0x124/0x1f0 [<000000009c867628>] nfs4_proc_lock+0x90/0x478 [<000000001686bd74>] do_setlk+0x64/0xe8 [<00000000e01500d4>] nfs_lock+0xe8/0x1f0 [<000000004f387d8d>] vfs_lock_file+0x18/0x40 [<00000000656ab79b>] do_lock_file_wait+0x68/0xf8 [<00000000f17c4a4b>] fcntl_setlk+0x224/0x280 [<0000000052a242c6>] do_fcntl+0x418/0x730 [<000000004f47291a>] __arm64_sys_fcntl+0x84/0xd0 [<00000000d6856e01>] el0_svc_common+0x80/0xf0 [<000000009c4bd1df>] el0_svc_handler+0x2c/0x80 [<00000000b1a0d479>] el0_svc+0x8/0xc [<0000000056c62a0f>] 0xffffffffffffffff This patch removes the original refcount_inc(&lsp->ls_count) that was paired with the memcpy() lock copying. Fixes: 7b587e1a5a6c ("NFS: use locks_copy_lock() to copy locks.") Cc: # 5.0.x- Cc: NeilBrown Signed-off-by: Catalin Marinas --- fs/nfs/nfs4proc.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 4dbb0ee23432..6d2812a39287 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6301,7 +6301,6 @@ static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl, p->arg.seqid = seqid; p->res.seqid = seqid; p->lsp = lsp; - refcount_inc(&lsp->ls_count); /* Ensure we don't close file until we're done freeing locks! */ p->ctx = get_nfs_open_context(ctx); p->l_ctx = nfs_get_lock_context(ctx); @@ -6526,7 +6525,6 @@ static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl, p->res.lock_seqid = p->arg.lock_seqid; p->lsp = lsp; p->server = server; - refcount_inc(&lsp->ls_count); p->ctx = get_nfs_open_context(ctx); locks_init_lock(&p->fl); locks_copy_lock(&p->fl, fl);