From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751358AbdBTWHe (ORCPT ); Mon, 20 Feb 2017 17:07:34 -0500 Received: from mail-ua0-f194.google.com ([209.85.217.194]:35164 "EHLO mail-ua0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbdBTWHc (ORCPT ); Mon, 20 Feb 2017 17:07:32 -0500 MIME-Version: 1.0 X-Originating-IP: [108.49.102.27] In-Reply-To: <1487585948-6401-16-git-send-email-elena.reshetova@intel.com> References: <1487585948-6401-1-git-send-email-elena.reshetova@intel.com> <1487585948-6401-16-git-send-email-elena.reshetova@intel.com> From: Paul Moore Date: Mon, 20 Feb 2017 17:07:25 -0500 Message-ID: Subject: Re: [PATCH 15/19] kernel: convert audit_tree.count from atomic_t to refcount_t To: Elena Reshetova Cc: linux-kernel@vger.kernel.org, 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, Eric Paris , akpm@linux-foundation.org, arnd@arndb.de, luto@kernel.org, Hans Liljestrand , Kees Cook , David Windsor Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 20, 2017 at 5:19 AM, Elena Reshetova wrote: > 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/audit_tree.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) No objection on my end, same for patch 16/19. I have no problem merging both these patches into the audit/next branch after the merge window, is that your goal or are you merging these via a different tree? > diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c > index 7b44195..7ed617b 100644 > --- a/kernel/audit_tree.c > +++ b/kernel/audit_tree.c > @@ -9,7 +9,7 @@ struct audit_tree; > struct audit_chunk; > > struct audit_tree { > - atomic_t count; > + refcount_t count; > int goner; > struct audit_chunk *root; > struct list_head chunks; > @@ -77,7 +77,7 @@ static struct audit_tree *alloc_tree(const char *s) > > tree = kmalloc(sizeof(struct audit_tree) + strlen(s) + 1, GFP_KERNEL); > if (tree) { > - atomic_set(&tree->count, 1); > + refcount_set(&tree->count, 1); > tree->goner = 0; > INIT_LIST_HEAD(&tree->chunks); > INIT_LIST_HEAD(&tree->rules); > @@ -91,12 +91,12 @@ static struct audit_tree *alloc_tree(const char *s) > > static inline void get_tree(struct audit_tree *tree) > { > - atomic_inc(&tree->count); > + refcount_inc(&tree->count); > } > > static inline void put_tree(struct audit_tree *tree) > { > - if (atomic_dec_and_test(&tree->count)) > + if (refcount_dec_and_test(&tree->count)) > kfree_rcu(tree, head); > } > -- paul moore www.paul-moore.com