VMCI: Fix integer overflow in VMCI handle arrays
commit 1c2eb5b2853c9f513690ba6b71072d8eb65da16a upstream.
The VMCI handle array has an integer overflow in
vmci_handle_arr_append_entry when it tries to expand the array. This can be
triggered from a guest, since the doorbell link hypercall doesn't impose a
limit on the number of doorbell handles that a VM can create in the
hypervisor, and these handles are stored in a handle array.
In this change, we introduce a mandatory max capacity for handle
arrays/lists to avoid excessive memory usage.
Signed-off-by: Vishnu Dasa <vdasa@vmware.com>
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/vmw_vmci/vmci_handle_array.c b/drivers/misc/vmw_vmci/vmci_handle_array.c
index 344973a..917e18a 100644
--- a/drivers/misc/vmw_vmci/vmci_handle_array.c
+++ b/drivers/misc/vmw_vmci/vmci_handle_array.c
@@ -16,24 +16,29 @@
#include <linux/slab.h>
#include "vmci_handle_array.h"
-static size_t handle_arr_calc_size(size_t capacity)
+static size_t handle_arr_calc_size(u32 capacity)
{
- return sizeof(struct vmci_handle_arr) +
+ return VMCI_HANDLE_ARRAY_HEADER_SIZE +
capacity * sizeof(struct vmci_handle);
}
-struct vmci_handle_arr *vmci_handle_arr_create(size_t capacity)
+struct vmci_handle_arr *vmci_handle_arr_create(u32 capacity, u32 max_capacity)
{
struct vmci_handle_arr *array;
+ if (max_capacity == 0 || capacity > max_capacity)
+ return NULL;
+
if (capacity == 0)
- capacity = VMCI_HANDLE_ARRAY_DEFAULT_SIZE;
+ capacity = min((u32)VMCI_HANDLE_ARRAY_DEFAULT_CAPACITY,
+ max_capacity);
array = kmalloc(handle_arr_calc_size(capacity), GFP_ATOMIC);
if (!array)
return NULL;
array->capacity = capacity;
+ array->max_capacity = max_capacity;
array->size = 0;
return array;
@@ -44,27 +49,34 @@ void vmci_handle_arr_destroy(struct vmci_handle_arr *array)
kfree(array);
}
-void vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
- struct vmci_handle handle)
+int vmci_handle_arr_append_entry(struct vmci_handle_arr **array_ptr,
+ struct vmci_handle handle)
{
struct vmci_handle_arr *array = *array_ptr;
if (unlikely(array->size >= array->capacity)) {
/* reallocate. */
struct vmci_handle_arr *new_array;
- size_t new_capacity = array->capacity * VMCI_ARR_CAP_MULT;
- size_t new_size = handle_arr_calc_size(new_capacity);
+ u32 capacity_bump = min(array->max_capacity - array->capacity,
+ array->capacity);
+ size_t new_size = handle_arr_calc_size(array->capacity +
+ capacity_bump);
+
+ if (array->size >= array->max_capacity)
+ return VMCI_ERROR_NO_MEM;
new_array = krealloc(array, new_size, GFP_ATOMIC);
if (!new_array)
- return;
+ return VMCI_ERROR_NO_MEM;
- new_array->capacity = new_capacity;
+ new_array->capacity += capacity_bump;
*array_ptr = array = new_array;
}
array->entries[array->size] = handle;
array->size++;
+
+ return VMCI_SUCCESS;
}
/*
@@ -74,7 +86,7 @@ struct vmci_handle vmci_handle_arr_remove_entry(struct vmci_handle_arr *array,
struct vmci_handle entry_handle)
{
struct vmci_handle handle = VMCI_INVALID_HANDLE;
- size_t i;
+ u32 i;
for (i = 0; i < array->size; i++) {
if (vmci_handle_is_equal(array->entries[i], entry_handle)) {
@@ -109,7 +121,7 @@ struct vmci_handle vmci_handle_arr_remove_tail(struct vmci_handle_arr *array)
* Handle at given index, VMCI_INVALID_HANDLE if invalid index.
*/
struct vmci_handle
-vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
+vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, u32 index)
{
if (unlikely(index >= array->size))
return VMCI_INVALID_HANDLE;
@@ -120,7 +132,7 @@ vmci_handle_arr_get_entry(const struct vmci_handle_arr *array, size_t index)
bool vmci_handle_arr_has_entry(const struct vmci_handle_arr *array,
struct vmci_handle entry_handle)
{
- size_t i;
+ u32 i;
for (i = 0; i < array->size; i++)
if (vmci_handle_is_equal(array->entries[i], entry_handle))