From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754995Ab3IKPij (ORCPT ); Wed, 11 Sep 2013 11:38:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13080 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752981Ab3IKPih (ORCPT ); Wed, 11 Sep 2013 11:38:37 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH] CacheFiles: Fix memory leak in cachefiles_check_auxdata error paths To: milosz@adfin.com From: David Howells Cc: ceph-devel@vger.kernel.org, linux-cachefs@redhat.com, linux-kernel@vger.kernel.org, Hongyi Jia , Josh Boyer Date: Wed, 11 Sep 2013 16:38:32 +0100 Message-ID: <20130911153832.19151.65721.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josh Boyer In cachefiles_check_auxdata(), we allocate auxbuf but fail to free it if we get determine there's an error or that the data is stale. Further, assigning the output of vfs_getxattr() to auxbuf->len gives problems with checking for errors as auxbuf->len is a u16. We don't actually need to set auxbuf->len, so keep the length in a variable for now. We shouldn't need to check the upper limit of the buffer as an overflow there should be indicated by -ERANGE. Whilst we're at it, fscache_check_aux() returns an enum value, not an int, so assign it to an appropriately typed variable rather than to ret. Signed-off-by: Josh Boyer Signed-off-by: David Howells cc: Hongyi Jia cc: Milosz Tanski --- fs/cachefiles/xattr.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c index 34c88b8..12b0eef 100644 --- a/fs/cachefiles/xattr.c +++ b/fs/cachefiles/xattr.c @@ -162,8 +162,9 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object, int cachefiles_check_auxdata(struct cachefiles_object *object) { struct cachefiles_xattr *auxbuf; + enum fscache_checkaux validity; struct dentry *dentry = object->dentry; - unsigned int dlen; + ssize_t xlen; int ret; ASSERT(dentry); @@ -174,22 +175,22 @@ int cachefiles_check_auxdata(struct cachefiles_object *object) if (!auxbuf) return -ENOMEM; - auxbuf->len = vfs_getxattr(dentry, cachefiles_xattr_cache, - &auxbuf->type, 512 + 1); - if (auxbuf->len < 1) - return -ESTALE; - - if (auxbuf->type != object->fscache.cookie->def->type) - return -ESTALE; + xlen = vfs_getxattr(dentry, cachefiles_xattr_cache, + &auxbuf->type, 512 + 1); + ret = -ESTALE; + if (xlen < 1 || + auxbuf->type != object->fscache.cookie->def->type) + goto error; - dlen = auxbuf->len - 1; - ret = fscache_check_aux(&object->fscache, &auxbuf->data, dlen); + xlen--; + validity = fscache_check_aux(&object->fscache, &auxbuf->data, xlen); + if (validity != FSCACHE_CHECKAUX_OKAY) + goto error; + ret = 0; +error: kfree(auxbuf); - if (ret != FSCACHE_CHECKAUX_OKAY) - return -ESTALE; - - return 0; + return ret; } /*