This is a note to let you know that I've just added the patch titled
KVM: x86: fix typo in __try_cmpxchg_user causing non-atomicness
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-fix-typo-in-__try_cmpxchg_user-causing-non-atomicness.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 33fbe6befa622c082f7d417896832856814bdde0 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Date: Thu, 12 May 2022 13:14:20 +0300
Subject: KVM: x86: fix typo in __try_cmpxchg_user causing non-atomicness
From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
commit 33fbe6befa622c082f7d417896832856814bdde0 upstream.
This shows up as a TDP MMU leak when running nested. Non-working cmpxchg on L0
relies makes L1 install two different shadow pages under same spte, and one of
them is leaked.
Fixes: 1c2361f667f36 ("KVM: x86: Use __try_cmpxchg_user() to emulate atomic accesses")
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Message-Id: <20220512101420.306759-1-mlevitsk@xxxxxxxxxx>
Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/x86.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6933,7 +6933,7 @@ static int emulator_cmpxchg_emulated(str
goto emul_write;
hva = kvm_vcpu_gfn_to_hva(vcpu, gpa_to_gfn(gpa));
- if (kvm_is_error_hva(addr))
+ if (kvm_is_error_hva(hva))
goto emul_write;
hva += offset_in_page(gpa);
Patches currently in stable-queue which might be from mlevitsk@xxxxxxxxxx are
queue-5.15/kvm-x86-fix-typo-in-__try_cmpxchg_user-causing-non-atomicness.patch
