From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [Patch] x86/mm: Prevent leaking domain mappings in paging_log_dirty_op() Date: Tue, 10 Dec 2013 13:53:56 +0000 Message-ID: <1386683636-5836-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Andrew Cooper , Keir Fraser , Jan Beulich , Tim Deegan List-Id: xen-devel@lists.xenproject.org Coverity ID: 1135374 1135375 1135376 1135377 If {copy_to,clear}_guest_offset() fails, we would leak the domain mappings for l4 thru l1. Fixing this requires having conditional unmaps on the faulting path, which in turn requires explicitly initialising the pointers to NULL because of the early ENOMEM exit. Signed-off-by: Andrew Cooper CC: Keir Fraser CC: Jan Beulich CC: Tim Deegan --- xen/arch/x86/mm/paging.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c index 4ba7669..3530766 100644 --- a/xen/arch/x86/mm/paging.c +++ b/xen/arch/x86/mm/paging.c @@ -330,8 +330,8 @@ int paging_log_dirty_op(struct domain *d, struct xen_domctl_shadow_op *sc) { int rv = 0, clean = 0, peek = 1; unsigned long pages = 0; - mfn_t *l4, *l3, *l2; - unsigned long *l1; + mfn_t *l4 = NULL, *l3 = NULL, *l2 = NULL; + unsigned long *l1 = NULL; int i4, i3, i2; domain_pause(d); @@ -432,6 +432,15 @@ int paging_log_dirty_op(struct domain *d, struct xen_domctl_shadow_op *sc) return rv; out: + if ( l1 ) + unmap_domain_page(l1); + if ( l2 ) + unmap_domain_page(l2); + if ( l3 ) + unmap_domain_page(l3); + if ( l4 ) + unmap_domain_page(l4); + paging_unlock(d); domain_unpause(d); return rv; -- 1.7.10.4