[PATCH v2 23/24] vduse: use vmalloc_array and vcalloc

From: Julia Lawall
Date: Tue Jun 27 2023 - 10:47:15 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. The position of this patch in the series changed
accordingly.

drivers/vdpa/vdpa_user/iova_domain.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff -u -p a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c
--- a/drivers/vdpa/vdpa_user/iova_domain.c
+++ b/drivers/vdpa/vdpa_user/iova_domain.c
@@ -571,8 +571,8 @@ vduse_domain_create(unsigned long iova_l

domain->iova_limit = iova_limit;
domain->bounce_size = PAGE_ALIGN(bounce_size);
- domain->bounce_maps = vzalloc(bounce_pfns *
- sizeof(struct vduse_bounce_map));
+ domain->bounce_maps = vcalloc(bounce_pfns,
+ sizeof(struct vduse_bounce_map));
if (!domain->bounce_maps)
goto err_map;