[PATCH 5.15 102/230] KVM: use __vcalloc for very large allocations

Greg Kroah-Hartman
2022-07-11T09:49:56Z

From: Paolo Bonzini <pbonzini@redhat.com>

[ Upstream commit 37b2a6510a48ca361ced679f92682b7b7d7d0330 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kvm/book3s_hv_uvmem.c | 2 +-
arch/x86/kvm/mmu/page_track.c | 4 ++--
arch/x86/kvm/x86.c | 4 ++--
virt/kvm/kvm_main.c | 4 ++--
4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 3fbe710ff839..3d4ee75b0fb7 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot)
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;
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 21427e84a82e..630ae70bb6bd 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -36,8 +36,8 @@ int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,

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;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 39aaa21e28f7..8974884ef2ad 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11552,7 +11552,7 @@ static int memslot_rmap_alloc(struct kvm_memory_slot *slot,
if (slot->arch.rmap[i])
continue;

- 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;
@@ -11633,7 +11633,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm,

lpages = __kvm_mmu_slot_lpages(slot, npages, level);

- linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
+ linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
if (!linfo)
goto out_free;

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fefdf3a6dae3..99c591569815 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1255,9 +1255,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
*/
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;

--
2.35.1