From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Ashutosh Desai <ashutoshdesai993@gmail.com>
Subject: [PATCH v2 3/6] KVM: SEV: Explicitly validate the dst buffer for debug operations
Date: Thu, 16 Apr 2026 16:10:40 -0700 [thread overview]
Message-ID: <20260416231043.3402410-4-seanjc@google.com> (raw)
In-Reply-To: <20260416231043.3402410-1-seanjc@google.com>
When encrypting/decrypting guest memory, explicitly check that the
destination is non-NULL and doesn't wrap instead of subtly relying on
sev_pin_memory() to perform the check. This will allow adding and using
a more focused single-page pinning helper.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/sev.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index b9d7bd868e0b..9d2044fd910d 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1357,9 +1357,11 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
if (copy_from_user(&debug, u64_to_user_ptr(argp->data), sizeof(debug)))
return -EFAULT;
- if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
+ if (!debug.len || !debug.src_uaddr || !debug.dst_uaddr)
return -EINVAL;
- if (!debug.dst_uaddr)
+
+ if (debug.src_uaddr + debug.len < debug.src_uaddr ||
+ debug.dst_uaddr + debug.len < debug.dst_uaddr)
return -EINVAL;
vaddr = debug.src_uaddr;
--
2.54.0.rc1.513.gad8abe7a5a-goog
next prev parent reply other threads:[~2026-04-16 23:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-16 23:10 [PATCH v2 0/6] KVM: SEV: sev_dbg_crypt() fix and overhaul Sean Christopherson
2026-04-16 23:10 ` [PATCH v2 1/6] KVM: SVM: Fix page overflow in sev_dbg_crypt() for ENCRYPT path Sean Christopherson
2026-04-16 23:10 ` [PATCH v2 2/6] KVM: selftests: Add a test to verify SEV {en,de}crypt debug ioctls Sean Christopherson
2026-04-16 23:10 ` Sean Christopherson [this message]
2026-04-16 23:10 ` [PATCH v2 4/6] KVM: SEV: Add helper function to pin/unpin a single page Sean Christopherson
2026-04-16 23:10 ` [PATCH v2 5/6] KVM: SEV: Rewrite logic to {de,en}crypt memory for debug Sean Christopherson
2026-04-16 23:10 ` [PATCH v2 6/6] KVM: SEV: Allocate only as many bytes as needed for temp crypt buffers Sean Christopherson
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