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From:   Julia Lawall <Julia.Lawall@inria.fr>
To:     Manivannan Sadhasivam <mani@kernel.org>
Cc:     kernel-janitors@vger.kernel.org, keescook@chromium.org,
        christophe.jaillet@wanadoo.fr, kuba@kernel.org,
        mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 10/24] bus: mhi: host: use vmalloc_array and vcalloc
Date:   Tue, 27 Jun 2023 16:43:25 +0200
Message-Id: <20230627144339.144478-11-Julia.Lawall@inria.fr>
In-Reply-To: <20230627144339.144478-1-Julia.Lawall@inria.fr>
References: <20230627144339.144478-1-Julia.Lawall@inria.fr>
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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>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
v2: Use vmalloc_array and vcalloc instead of array_size.
This also leaves a multiplication of a constant by a sizeof
as is.  Two patches are thus dropped from the series.

 drivers/bus/mhi/host/init.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -u -p a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -759,7 +759,7 @@ static int parse_ch_cfg(struct mhi_contr
 	 * 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;