[PATCH] KVM: Array access out of bounds

Liu Jing liujing at cmss.chinamobile.com
Wed Oct 23 23:01:11 AEDT 2024


In the kvmppc_mmu_book3s_64_xlate function,
r = be64_to_cpu(pteg[i+1]); i used is 16 after the last loop and adding 1 will cross the line.

Signed-off-by: Liu Jing <liujing at cmss.chinamobile.com>

diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index 61290282fd9e..75d2b284c4b4 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -284,11 +284,16 @@ static int kvmppc_mmu_book3s_64_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 		second = true;
 		goto do_second;
 	}
+	if (i < 14) {
+		r = be64_to_cpu(pteg[i+1]);
+		pp = (r & HPTE_R_PP) | key;
+		if (r & HPTE_R_PP0)
+			pp |= 8;
+	} else {
+		dprintk("KVM: Index out of bounds!\n");
+		goto no_page_found;
+	}
 
-	r = be64_to_cpu(pteg[i+1]);
-	pp = (r & HPTE_R_PP) | key;
-	if (r & HPTE_R_PP0)
-		pp |= 8;
 
 	gpte->eaddr = eaddr;
 	gpte->vpage = kvmppc_mmu_book3s_64_ea_to_vp(vcpu, eaddr, data);
-- 
2.27.0





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