linux-kernel - [PATCH 5.14 112/169] KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in

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:   Mon, 25 Oct 2021 21:14:53 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Maxim Levitsky <mlevitsk@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 5.14 112/169] KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out

From: Paolo Bonzini <pbonzini@...hat.com>

commit 0d33b1baeb6ca7165d5ed4fdd1a8f969985e35b9 upstream.

Currently emulator_pio_in clears vcpu->arch.pio.count twice if
emulator_pio_in_out performs kernel PIO.  Move the clear into
emulator_pio_out where it is actually necessary.

No functional change intended.

Cc: stable@...r.kernel.org
Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest")
Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/x86/kvm/x86.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6915,10 +6915,8 @@ static int emulator_pio_in_out(struct kv
 	vcpu->arch.pio.count  = count;
 	vcpu->arch.pio.size = size;
 
-	if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
-		vcpu->arch.pio.count = 0;
+	if (!kernel_pio(vcpu, vcpu->arch.pio_data))
 		return 1;
-	}
 
 	vcpu->run->exit_reason = KVM_EXIT_IO;
 	vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
@@ -6964,9 +6962,16 @@ static int emulator_pio_out(struct kvm_v
 			    unsigned short port, const void *val,
 			    unsigned int count)
 {
+	int ret;
+
 	memcpy(vcpu->arch.pio_data, val, size * count);
 	trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
-	return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
+	ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
+	if (ret)
+                vcpu->arch.pio.count = 0;
+
+        return ret;
+
 }
 
 static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,