[PATCH v2 04/24] gve: use vmalloc_array and vcalloc

From: Julia Lawall
Date: Tue Jun 27 2023 - 10:45:48 EST


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@xxxxxxxx>

---
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/net/ethernet/google/gve/gve_tx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff -u -p a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c
--- a/drivers/net/ethernet/google/gve/gve_tx.c
+++ b/drivers/net/ethernet/google/gve/gve_tx.c
@@ -248,7 +248,7 @@ static int gve_tx_alloc_ring(struct gve_
tx->mask = slots - 1;

/* alloc metadata */
- tx->info = vzalloc(sizeof(*tx->info) * slots);
+ tx->info = vcalloc(slots, sizeof(*tx->info));
if (!tx->info)
return -ENOMEM;