From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 8 Mar 2022 04:49:37 -0500
Subject: KVM: use __vcalloc for very large allocations
Git-commit: 37b2a6510a48ca361ced679f92682b7b7d7d0330
Patch-mainline: v5.18-rc1
References: bsc#1198110

Allocations whose size is related to the memslot size can be arbitrarily
large.  Do not use kvzalloc/kvcalloc, as those are limited to "not crazy"
sizes that fit in 32 bits.

Cc: stable@vger.kernel.org
Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>
---
 arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +-
 arch/x86/kvm/mmu/page_track.c      | 7 ++++---
 arch/x86/kvm/x86.c                 | 4 ++--
 virt/kvm/kvm_main.c                | 4 ++--
 4 files changed, 9 insertions(+), 8 deletions(-)

--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -251,7 +251,7 @@
 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
-	p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns)));
+	p->pfns = vcalloc(slot->npages, sizeof(*p->pfns));
 	if (!p->pfns) {
 		kfree(p);
 		return -ENOMEM;
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -35,8 +35,8 @@
 
 	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
 		slot->arch.gfn_track[i] =
-			kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]),
-				 GFP_KERNEL_ACCOUNT);
+			__vcalloc(npages, sizeof(*slot->arch.gfn_track[i]),
+				  GFP_KERNEL_ACCOUNT);
 		if (!slot->arch.gfn_track[i])
 			goto track_free;
 	}
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11246,7 +11246,7 @@
 
 		WARN_ON(slot->arch.rmap[i]);
 
-		slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT);
+		slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT);
 		if (!slot->arch.rmap[i]) {
 			memslot_rmap_free(slot);
 			return -ENOMEM;
@@ -11328,7 +11328,7 @@
 		lpages = gfn_to_index(slot->base_gfn + npages - 1,
 				      slot->base_gfn, level) + 1;
 
-		linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
+		linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
 		if (!linfo)
 			goto out_free;
 
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1170,9 +1170,9 @@
  */
 static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot)
 {
-	unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
+	unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot);
 
-	memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT);
+	memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT);
 	if (!memslot->dirty_bitmap)
 		return -ENOMEM;