Re: FAILED: patch "[PATCH] KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent" failed to apply to 5.10-stable tree

[Sudip Mukherjee <sudipm.mukherjee@gmail.com>]

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Hi Greg,

On Fri, Jun 03, 2022 at 05:15:15PM +0200, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.10-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Here is the backport along with eba04b20e486 ("KVM: x86: Account a variety
of miscellaneous allocations") which was needed for easier backporting.

--
Regards
Sudip

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From a32f2e2d390d929a371ea7baef2bad7e42d2d3ee Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Tue, 30 Mar 2021 19:30:25 -0700
Subject: [PATCH 1/2] KVM: x86: Account a variety of miscellaneous allocations

commit eba04b20e4861d9bdbd8470a13c0c6e824521a36 upstream.

Switch to GFP_KERNEL_ACCOUNT for a handful of allocations that are
clearly associated with a single task/VM.

Note, there are a several SEV allocations that aren't accounted, but
those can (hopefully) be fixed by using the local stack for memory.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210331023025.2485960-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 arch/x86/kvm/svm/nested.c | 4 ++--
 arch/x86/kvm/svm/sev.c    | 2 +-
 arch/x86/kvm/vmx/vmx.c    | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 23910e6a3f011..e7feaa7910ab3 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1198,8 +1198,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 
 	ret  = -ENOMEM;
-	ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL);
-	save = kzalloc(sizeof(*save), GFP_KERNEL);
+	ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL_ACCOUNT);
+	save = kzalloc(sizeof(*save), GFP_KERNEL_ACCOUNT);
 	if (!ctl || !save)
 		goto out_free;
 
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 6c82ef22985d9..a0c4da5f7d7fe 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -537,7 +537,7 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
 		}
 
 		ret = -ENOMEM;
-		blob = kmalloc(params.len, GFP_KERNEL);
+		blob = kmalloc(params.len, GFP_KERNEL_ACCOUNT);
 		if (!blob)
 			goto e_free;
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e729f65c67600..cc647dcc228b7 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -619,7 +619,7 @@ static int hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
 	 * evmcs in singe VM shares same assist page.
 	 */
 	if (!*p_hv_pa_pg)
-		*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL);
+		*p_hv_pa_pg = kzalloc(PAGE_SIZE, GFP_KERNEL_ACCOUNT);
 
 	if (!*p_hv_pa_pg)
 		return -ENOMEM;
-- 
2.30.2


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From 7479eecc9a8955aac994cad3ee5e6e123f0b2059 Mon Sep 17 00:00:00 2001
From: Ashish Kalra <ashish.kalra@amd.com>
Date: Mon, 16 May 2022 15:43:10 +0000
Subject: [PATCH 2/2] KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent
 kernel data leak

commit d22d2474e3953996f03528b84b7f52cc26a39403 upstream.

For some sev ioctl interfaces, the length parameter that is passed maybe
less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data
that PSP firmware returns. In this case, kmalloc will allocate memory
that is the size of the input rather than the size of the data.
Since PSP firmware doesn't fully overwrite the allocated buffer, these
sev ioctl interface may return uninitialized kernel slab memory.

Reported-by: Andy Nguyen <theflow@google.com>
Suggested-by: David Rientjes <rientjes@google.com>
Suggested-by: Peter Gonda <pgonda@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: eaf78265a4ab3 ("KVM: SVM: Move SEV code to separate file")
Fixes: 2c07ded06427d ("KVM: SVM: add support for SEV attestation command")
Fixes: 4cfdd47d6d95a ("KVM: SVM: Add KVM_SEV SEND_START command")
Fixes: d3d1af85e2c75 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command")
Fixes: eba04b20e4861 ("KVM: x86: Account a variety of miscellaneous allocations")
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Peter Gonda <pgonda@google.com>
Message-Id: <20220516154310.3685678-1-Ashish.Kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
---
 arch/x86/kvm/svm/sev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index a0c4da5f7d7fe..7397cc449e2fc 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -537,7 +537,7 @@ static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
 		}
 
 		ret = -ENOMEM;
-		blob = kmalloc(params.len, GFP_KERNEL_ACCOUNT);
+		blob = kzalloc(params.len, GFP_KERNEL_ACCOUNT);
 		if (!blob)
 			goto e_free;
 
@@ -676,7 +676,7 @@ static int __sev_dbg_decrypt_user(struct kvm *kvm, unsigned long paddr,
 	if (!IS_ALIGNED(dst_paddr, 16) ||
 	    !IS_ALIGNED(paddr,     16) ||
 	    !IS_ALIGNED(size,      16)) {
-		tpage = (void *)alloc_page(GFP_KERNEL);
+		tpage = (void *)alloc_page(GFP_KERNEL | __GFP_ZERO);
 		if (!tpage)
 			return -ENOMEM;
 
-- 
2.30.2