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authorPaolo Bonzini <pbonzini@redhat.com>2022-11-23 18:52:29 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2022-11-23 18:59:45 -0500
commitfe08e36be9ecbf6b38714a77c97b1d25b7a6e4b0 (patch)
tree9ad343989dfe2029c80f8e4f86c828504edba428 /virt
parent47b0c2e4c220f2251fd8dcfbb44479819c715e15 (diff)
parent8332f0ed4f187c7b700831bd7cc83ce180a944b9 (diff)
downloadlinux-fe08e36be9ecbf6b38714a77c97b1d25b7a6e4b0.tar.gz
Merge branch 'kvm-dwmw2-fixes' into HEAD
This brings in a few important fixes for Xen emulation.
While nobody should be enabling it, the bug effectively
allows userspace to read arbitrary memory.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/pfncache.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index 346e47f15572..7c248193ca26 100644
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -297,7 +297,12 @@ int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
 	if (!gpc->valid || old_uhva != gpc->uhva) {
 		ret = hva_to_pfn_retry(kvm, gpc);
 	} else {
-		/* If the HVA→PFN mapping was already valid, don't unmap it. */
+		/*
+		 * If the HVA→PFN mapping was already valid, don't unmap it.
+		 * But do update gpc->khva because the offset within the page
+		 * may have changed.
+		 */
+		gpc->khva = old_khva + page_offset;
 		old_pfn = KVM_PFN_ERR_FAULT;
 		old_khva = NULL;
 		ret = 0;