Messages in this thread Patch in this message | | | From | Julia Lawall <> | Subject | [PATCH v2 17/24] kcov: use vmalloc_array and vcalloc | Date | Tue, 27 Jun 2023 16:43:32 +0200 |
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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.
kernel/kcov.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff -u -p a/kernel/kcov.c b/kernel/kcov.c --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -901,7 +901,7 @@ void kcov_remote_start(u64 handle) /* Can only happen when in_task(). */ if (!area) { local_unlock_irqrestore(&kcov_percpu_data.lock, flags); - area = vmalloc(size * sizeof(unsigned long)); + area = vmalloc_array(size, sizeof(unsigned long)); if (!area) { kcov_put(kcov); return;
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