linux-kernel - [PATCH 33/52] KVM: MMU: Fix potential memory leak with smp real-mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 30 Dec 2007 09:10:19 +0200
From:	Avi Kivity <avi@...ranet.com>
To:	linux-kernel@...r.kernel.org, kvm-devel@...ts.sourceforge.net
Cc:	Izik Eidus <izike@...ranet.com>
Subject: [PATCH 33/52] KVM: MMU: Fix potential memory leak with smp real-mode

From: Izik Eidus <izike@...ranet.com>

When we map a page, we check whether some other vcpu mapped it for us and if
so, bail out.  But we should decrease the refcount on the page as we do so.

Signed-off-by: Izik Eidus <izike@...ranet.com>
Signed-off-by: Avi Kivity <avi@...ranet.com>
---
 drivers/kvm/mmu.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 87d8e70..8add4d5 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -907,8 +907,10 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
 
 			pte = table[index];
 			was_rmapped = is_rmap_pte(pte);
-			if (is_shadow_present_pte(pte) && is_writeble_pte(pte))
+			if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {
+				kvm_release_page(pfn_to_page(p >> PAGE_SHIFT));
 				return 0;
+			}
 			mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
 			page_header_update_slot(vcpu->kvm, table, v);
 			table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
-- 
1.5.3.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/