public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Peter Xu <peterx@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
	peterx@redhat.com,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Steffen Dirkwinkel <kernel-bugs@steffen.cc>
Subject: [PATCH 2/2] KVM: X86: Fix null pointer reference for KVM_GET_MSRS
Date: Sun, 25 Oct 2020 14:53:34 -0400	[thread overview]
Message-ID: <20201025185334.389061-3-peterx@redhat.com> (raw)
In-Reply-To: <20201025185334.389061-1-peterx@redhat.com>

kvm_msr_ignored_check() could trigger a null pointer reference if ignore_msrs=Y
and report_ignore_msrs=Y when try to fetch an invalid feature msr using the
global KVM_GET_MSRS.  Degrade the error report to not rely on vcpu since that
information (index, rip) is not as important as msr index/data after all.

Fixes: 12bc2132b15e0a96
Reported-by: Steffen Dirkwinkel <kernel-bugs@steffen.cc>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 arch/x86/kvm/x86.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ce856e0ece84..5993fbd6d2c5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -259,8 +259,8 @@ static int kvm_msr_ignored_check(struct kvm_vcpu *vcpu, u32 msr,
 
 	if (ignore_msrs) {
 		if (report_ignored_msrs)
-			vcpu_unimpl(vcpu, "ignored %s: 0x%x data 0x%llx\n",
-				    op, msr, data);
+			kvm_pr_unimpl("ignored %s: 0x%x data 0x%llx\n",
+				      op, msr, data);
 		/* Mask the error */
 		return 0;
 	} else {
-- 
2.26.2


  parent reply	other threads:[~2020-10-25 18:53 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-25 18:53 [PATCH 0/2] Fix null pointer dereference in kvm_msr_ignored_check Peter Xu
2020-10-25 18:53 ` [PATCH 1/2] KVM: selftests: Add get featured msrs test case Peter Xu
2020-10-26  8:58   ` Vitaly Kuznetsov
2020-10-26  9:08     ` Andrew Jones
2020-10-31 15:34     ` Peter Xu
2020-10-25 18:53 ` Peter Xu [this message]
2020-10-26  9:07   ` [PATCH 2/2] KVM: X86: Fix null pointer reference for KVM_GET_MSRS Vitaly Kuznetsov
2020-10-31 14:06   ` Paolo Bonzini
2020-10-31 15:27     ` Peter Xu

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=20201025185334.389061-3-peterx@redhat.com \
    --to=peterx@redhat.com \
    --cc=kernel-bugs@steffen.cc \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=vkuznets@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* 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