kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: kvm@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	stable <stable@kernel.org>, Xingyuan Mo <hdthky0@gmail.com>
Subject: [PATCH] kvm: initialize all of the kvm_debugregs structure before sending it to userspace
Date: Tue, 14 Feb 2023 11:33:04 +0100	[thread overview]
Message-ID: <20230214103304.3689213-1-gregkh@linuxfoundation.org> (raw)

When calling the KVM_GET_DEBUGREGS ioctl, on some configurations, there
might be some unitialized portions of the kvm_debugregs structure that
could be copied to userspace.  Prevent this as is done in the other kvm
ioctls, by setting the whole structure to 0 before copying anything into

Bonus is that this reduces the lines of code as the explicit flag
setting and reserved space zeroing out can be removed.

Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <x86@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable <stable@kernel.org>
Reported-by: Xingyuan Mo <hdthky0@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 arch/x86/kvm/x86.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index da4bbd043a7b..50a95c8082fa 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5254,12 +5254,11 @@ static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
 	unsigned long val;
+	memset(dbgregs, 0, sizeof(*dbgregs));
 	memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
 	kvm_get_dr(vcpu, 6, &val);
 	dbgregs->dr6 = val;
 	dbgregs->dr7 = vcpu->arch.dr7;
-	dbgregs->flags = 0;
-	memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
 static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,

             reply	other threads:[~2023-02-14 10:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-14 10:33 Greg Kroah-Hartman [this message]
2023-02-14 12:03 ` [PATCH] kvm: initialize all of the kvm_debugregs structure before sending it to userspace Xingyuan Mo
2023-02-16 17:30 ` Paolo Bonzini
2023-02-20 10:40 ` Mathias Krause
2023-04-03 19:45   ` Mathias Krause
2023-04-04 17:13     ` Sean Christopherson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230214103304.3689213-1-gregkh@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hdthky0@gmail.com \
    --cc=hpa@zytor.com \
    --cc=kvm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=seanjc@google.com \
    --cc=stable@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \


* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).