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authorVishnu DASA <vdasa@vmware.com>2019-05-24 18:13:10 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-21 17:04:05 +0300
commit1c2eb5b2853c9f513690ba6b71072d8eb65da16a (patch)
treedc58a16d48db90df7f58d96b18b0850c7d2b6f9b /include/linux/vmw_vmci_defs.h
parent84705f9f8c64cc3d8409ac63e5dd06ed97886fb7 (diff)
downloadlinux-1c2eb5b2853c9f513690ba6b71072d8eb65da16a.tar.xz
VMCI: Fix integer overflow in VMCI handle arrays
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>
Diffstat (limited to 'include/linux/vmw_vmci_defs.h')
-rw-r--r--include/linux/vmw_vmci_defs.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h
index 606504bf376a..fefb5292403b 100644
--- a/include/linux/vmw_vmci_defs.h
+++ b/include/linux/vmw_vmci_defs.h
@@ -62,9 +62,18 @@ enum {
/*
* A single VMCI device has an upper limit of 128MB on the amount of
- * memory that can be used for queue pairs.
+ * memory that can be used for queue pairs. Since each queue pair
+ * consists of at least two pages, the memory limit also dictates the
+ * number of queue pairs a guest can create.
*/
#define VMCI_MAX_GUEST_QP_MEMORY (128 * 1024 * 1024)
+#define VMCI_MAX_GUEST_QP_COUNT (VMCI_MAX_GUEST_QP_MEMORY / PAGE_SIZE / 2)
+
+/*
+ * There can be at most PAGE_SIZE doorbells since there is one doorbell
+ * per byte in the doorbell bitmap page.
+ */
+#define VMCI_MAX_GUEST_DOORBELL_COUNT PAGE_SIZE
/*
* Queues with pre-mapped data pages must be small, so that we don't pin