From patchwork Fri Jul 7 09:04:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9829821 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A0A57602CA for ; Fri, 7 Jul 2017 09:09:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D41928606 for ; Fri, 7 Jul 2017 09:09:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 81D7B28604; Fri, 7 Jul 2017 09:09:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 199DD28604 for ; Fri, 7 Jul 2017 09:09:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752775AbdGGJHZ (ORCPT ); Fri, 7 Jul 2017 05:07:25 -0400 Received: from mga07.intel.com ([134.134.136.100]:5732 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751AbdGGJHU (ORCPT ); Fri, 7 Jul 2017 05:07:20 -0400 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP; 07 Jul 2017 02:07:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,321,1496127600"; d="scan'208";a="284088788" Received: from unknown (HELO elena-ThinkPad-X230.fi.intel.com) ([10.237.72.73]) by fmsmga004.fm.intel.com with ESMTP; 07 Jul 2017 02:07:15 -0700 From: Elena Reshetova To: linux-kernel@vger.kernel.org Cc: cgroups@vger.kernel.org, linux-audit@redhat.com, linux-fsdevel@vger.kernel.org, peterz@infradead.org, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk, tj@kernel.org, mingo@redhat.com, hannes@cmpxchg.org, lizefan@huawei.com, acme@kernel.org, alexander.shishkin@linux.intel.com, eparis@redhat.com, akpm@linux-foundation.org, arnd@arndb.de, luto@kernel.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 09/15] kernel: convert uprobe.ref from atomic_t to refcount_t Date: Fri, 7 Jul 2017 12:04:23 +0300 Message-Id: <1499418269-3686-10-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1499418269-3686-1-git-send-email-elena.reshetova@intel.com> References: <1499418269-3686-1-git-send-email-elena.reshetova@intel.com> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- kernel/events/uprobes.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 456596d..ca093957 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -66,7 +66,7 @@ static struct percpu_rw_semaphore dup_mmap_sem; struct uprobe { struct rb_node rb_node; /* node in the rb tree */ - atomic_t ref; + refcount_t ref; struct rw_semaphore register_rwsem; struct rw_semaphore consumer_rwsem; struct list_head pending_list; @@ -371,13 +371,13 @@ set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long v static struct uprobe *get_uprobe(struct uprobe *uprobe) { - atomic_inc(&uprobe->ref); + refcount_inc(&uprobe->ref); return uprobe; } static void put_uprobe(struct uprobe *uprobe) { - if (atomic_dec_and_test(&uprobe->ref)) + if (refcount_dec_and_test(&uprobe->ref)) kfree(uprobe); } @@ -459,7 +459,7 @@ static struct uprobe *__insert_uprobe(struct uprobe *uprobe) rb_link_node(&uprobe->rb_node, parent, p); rb_insert_color(&uprobe->rb_node, &uprobes_tree); /* get access + creation ref */ - atomic_set(&uprobe->ref, 2); + refcount_set(&uprobe->ref, 2); return u; }