linux-kernel - [PATCH v7 04/11] KVM: pfncache: base offset check on khva rather than gpa

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]

Message-Id: <20231002095740.1472907-5-paul@xen.org>
Date:   Mon,  2 Oct 2023 09:57:33 +0000
From:   Paul Durrant <paul@....org>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Paul Durrant <pdurrant@...zon.com>,
        David Woodhouse <dwmw@...zon.co.uk>,
        Sean Christopherson <seanjc@...gle.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH v7 04/11] KVM: pfncache: base offset check on khva rather than gpa

From: Paul Durrant <pdurrant@...zon.com>

After a subsequent patch, the gpa may not always be set whereas khva will
(as long as the cache valid flag is also set).

No functional change intended.

Signed-off-by: Paul Durrant <pdurrant@...zon.com>
Reviewed-by: David Woodhouse <dwmw@...zon.co.uk>
---
Cc: Sean Christopherson <seanjc@...gle.com>
Cc: David Woodhouse <dwmw2@...radead.org>
Cc: Paolo Bonzini <pbonzini@...hat.com>
---
 virt/kvm/pfncache.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 17afbb464a70..37bcb4399780 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -83,15 +83,18 @@ bool kvm_gpc_check(struct gfn_to_pfn_cache *gpc, unsigned long len)
 	if (!gpc->active)
 		return false;
 
-	if ((gpc->gpa & ~PAGE_MASK) + len > PAGE_SIZE)
+	if (gpc->generation != slots->generation)
 		return false;
 
-	if (gpc->generation != slots->generation || kvm_is_error_hva(gpc->uhva))
+	if (kvm_is_error_hva(gpc->uhva))
 		return false;
 
 	if (!gpc->valid)
 		return false;
 
+	if (offset_in_page(gpc->khva) + len > PAGE_SIZE)
+		return false;
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(kvm_gpc_check);
-- 
2.39.2