bus: mhi: host: use vmalloc_array and vcalloc

Use vmalloc_array and vcalloc to protect against
multiplication overflows.

The changes were done using the following Coccinelle
semantic patch:

// <smpl>
@initialize:ocaml@
@@

let rename alloc =
  match alloc with
    "vmalloc" -> "vmalloc_array"
  | "vzalloc" -> "vcalloc"
  | _ -> failwith "unknown"

@@
    size_t e1,e2;
    constant C1, C2;
    expression E1, E2, COUNT, x1, x2, x3;
    typedef u8;
    typedef __u8;
    type t = {u8,__u8,char,unsigned char};
    identifier alloc = {vmalloc,vzalloc};
    fresh identifier realloc = script:ocaml(alloc) { rename alloc };
@@

(
      alloc(x1*x2*x3)
|
      alloc(C1 * C2)
|
      alloc((sizeof(t)) * (COUNT), ...)
|
-     alloc((e1) * (e2))
+     realloc(e1, e2)
|
-     alloc((e1) * (COUNT))
+     realloc(COUNT, e1)
|
-     alloc((E1) * (E2))
+     realloc(E1, E2)
)
// </smpl>

Reviewed-by: Jeffrey Hugo <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Manivannan Sadhasivam <[email protected]>

drivers/bus/mhi/host/init.c

@@ -759,7 +759,7 @@ static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
 	 * so to avoid any memory possible allocation failures, vzalloc is
 	 * used here
 	 */
-	mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
+	mhi_cntrl->mhi_chan = vcalloc(mhi_cntrl->max_chan,
 				      sizeof(*mhi_cntrl->mhi_chan));
 	if (!mhi_cntrl->mhi_chan)
 		return -ENOMEM;