From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933678Ab2JKBOi (ORCPT ); Wed, 10 Oct 2012 21:14:38 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:47984 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933642Ab2JKBOV (ORCPT ); Wed, 10 Oct 2012 21:14:21 -0400 X-Sasl-enc: jVv4V0Rqbkm75rmCW+a1gNOINoiGBtYCcsTfkSZ3YtSX 1349918060 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, KOSAKI Motohiro , Mel Gorman , Christoph Lameter , Josh Boyer , Andrew Morton , Linus Torvalds Subject: [ 103/120] mempolicy: fix refcount leak in mpol_set_shared_policy() Date: Thu, 11 Oct 2012 10:00:55 +0900 Message-Id: <20121011005846.031707189@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.rc0.18.gf84667d In-Reply-To: <20121011005825.364610894@linuxfoundation.org> References: <20121011005825.364610894@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: KOSAKI Motohiro commit 63f74ca21f1fad36d075e063f06dcc6d39fe86b2 upstream. When shared_policy_replace() fails to allocate new->policy is not freed correctly by mpol_set_shared_policy(). The problem is that shared mempolicy code directly call kmem_cache_free() in multiple places where it is easy to make a mistake. This patch creates an sp_free wrapper function and uses it. The bug was introduced pre-git age (IOW, before 2.6.12-rc2). [mgorman@suse.de: Editted changelog] Signed-off-by: KOSAKI Motohiro Signed-off-by: Mel Gorman Reviewed-by: Christoph Lameter Cc: Josh Boyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mempolicy.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2131,12 +2131,17 @@ mpol_shared_policy_lookup(struct shared_ return pol; } +static void sp_free(struct sp_node *n) +{ + mpol_put(n->policy); + kmem_cache_free(sn_cache, n); +} + static void sp_delete(struct shared_policy *sp, struct sp_node *n) { pr_debug("deleting %lx-l%lx\n", n->start, n->end); rb_erase(&n->nd, &sp->root); - mpol_put(n->policy); - kmem_cache_free(sn_cache, n); + sp_free(n); } static struct sp_node *sp_alloc(unsigned long start, unsigned long end, @@ -2275,7 +2280,7 @@ int mpol_set_shared_policy(struct shared } err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new); if (err && new) - kmem_cache_free(sn_cache, new); + sp_free(new); return err; } @@ -2292,9 +2297,7 @@ void mpol_free_shared_policy(struct shar while (next) { n = rb_entry(next, struct sp_node, nd); next = rb_next(&n->nd); - rb_erase(&n->nd, &p->root); - mpol_put(n->policy); - kmem_cache_free(sn_cache, n); + sp_delete(p, n); } mutex_unlock(&p->mutex); }