From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: vkuznets@redhat.com, mlevitsk@redhat.com, dmatlack@google.com,
seanjc@google.com
Subject: [PATCH 05/12] KVM: MMU: avoid NULL-pointer dereference on page freeing bugs
Date: Wed, 9 Feb 2022 12:00:13 -0500 [thread overview]
Message-ID: <20220209170020.1775368-6-pbonzini@redhat.com> (raw)
In-Reply-To: <20220209170020.1775368-1-pbonzini@redhat.com>
If kvm_mmu_free_roots encounters a PAE page table where a 64-bit page
table is expected, the result is a NULL pointer dereference. Instead
just WARN and exit.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu/mmu.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7b5765ced928..d0f2077bd798 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3201,6 +3201,8 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa,
return;
sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK);
+ if (WARN_ON(!sp))
+ return;
if (is_tdp_mmu_page(sp))
kvm_tdp_mmu_put_root(kvm, sp, false);
--
2.31.1
next prev parent reply other threads:[~2022-02-09 17:01 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-09 17:00 [PATCH 00/12] KVM: MMU: do not unload MMU roots on all role changes Paolo Bonzini
2022-02-09 17:00 ` [PATCH 01/12] KVM: x86: host-initiated EFER.LME write affects the MMU Paolo Bonzini
2022-02-10 22:49 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 02/12] KVM: MMU: move MMU role accessors to header Paolo Bonzini
2022-02-10 23:00 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 03/12] KVM: x86: do not deliver asynchronous page faults if CR0.PG=0 Paolo Bonzini
2022-02-10 23:10 ` Sean Christopherson
2022-02-10 23:14 ` Sean Christopherson
2022-02-10 23:16 ` Sean Christopherson
2022-02-11 11:16 ` Paolo Bonzini
2022-02-09 17:00 ` [PATCH 04/12] KVM: MMU: WARN if PAE roots linger after kvm_mmu_unload Paolo Bonzini
2022-02-10 23:20 ` Sean Christopherson
2022-02-11 11:18 ` Paolo Bonzini
2022-02-09 17:00 ` Paolo Bonzini [this message]
2022-02-11 0:24 ` [PATCH 05/12] KVM: MMU: avoid NULL-pointer dereference on page freeing bugs Sean Christopherson
2022-02-11 11:21 ` Paolo Bonzini
2022-02-09 17:00 ` [PATCH 06/12] KVM: MMU: rename kvm_mmu_reload Paolo Bonzini
2022-02-11 0:27 ` Sean Christopherson
2022-02-11 10:07 ` Paolo Bonzini
2022-02-11 16:16 ` Sean Christopherson
2022-02-11 16:52 ` Paolo Bonzini
2022-02-09 17:00 ` [PATCH 07/12] KVM: x86: use struct kvm_mmu_root_info for mmu->root Paolo Bonzini
2022-02-11 17:39 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 08/12] KVM: MMU: do not consult levels when freeing roots Paolo Bonzini
2022-02-11 0:41 ` Sean Christopherson
2022-02-11 0:54 ` Sean Christopherson
2022-02-11 1:07 ` Paolo Bonzini
2022-02-11 1:35 ` Sean Christopherson
2022-02-11 1:44 ` Sean Christopherson
2022-02-11 2:20 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 09/12] KVM: MMU: look for a cached PGD when going from 32-bit to 64-bit Paolo Bonzini
2022-02-11 1:32 ` Sean Christopherson
2022-02-11 1:37 ` Sean Christopherson
2022-02-11 10:09 ` Paolo Bonzini
2022-02-11 11:45 ` Paolo Bonzini
2022-02-11 17:38 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 10/12] KVM: MMU: load new PGD after the shadow MMU is initialized Paolo Bonzini
2022-02-11 17:45 ` Sean Christopherson
2022-02-11 17:47 ` Paolo Bonzini
2022-02-09 17:00 ` [PATCH 11/12] KVM: MMU: remove kvm_mmu_calc_root_page_role Paolo Bonzini
2022-02-11 17:53 ` Sean Christopherson
2022-02-09 17:00 ` [PATCH 12/12] KVM: x86: do not unload MMU roots on all role changes Paolo Bonzini
2022-02-11 9:08 ` Nikunj A. Dadhania
2022-02-11 18:48 ` Sean Christopherson
2022-02-14 16:34 ` Paolo Bonzini
2022-02-14 19:24 ` Sean Christopherson
2022-02-15 8:17 ` Paolo Bonzini
2022-02-09 17:07 ` [PATCH 00/12] KVM: MMU: " Sean Christopherson
2022-02-09 17:11 ` Paolo Bonzini
2022-02-09 17:16 ` 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:
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=20220209170020.1775368-6-pbonzini@redhat.com \
--to=pbonzini@redhat.com \
--cc=dmatlack@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mlevitsk@redhat.com \
--cc=seanjc@google.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;
as well as URLs for NNTP newsgroup(s).