On Fri, Apr 14, 2023 at 11:22 AM Jason Gerecke <killertofu@xxxxxxxxx> wrote:
>
> From: Jason Gerecke <killertofu@xxxxxxxxx>
>
> The strscpy function is able to return an error code when a copy would
> overflow the size of the destination. The copy is stopped and the buffer
> terminated before overflow actually occurs so it is safe to continue
> execution, but we should still produce a warning should this occur.
>
> Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx>
> Reviewed-by: Ping Cheng <ping.cheng@xxxxxxxxx>
> ---
> drivers/hid/wacom_sys.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
> index 8214896adadad..7192970d199a0 100644
> --- a/drivers/hid/wacom_sys.c
> +++ b/drivers/hid/wacom_sys.c
> @@ -2224,7 +2224,9 @@ static void wacom_update_name(struct wacom *wacom, const char *suffix)
> } else if (strstr(product_name, "Wacom") ||
> strstr(product_name, "wacom") ||
> strstr(product_name, "WACOM")) {
> - strscpy(name, product_name, sizeof(name));
> + if (strscpy(name, product_name, sizeof(name)) < 0) {
> + hid_warn(wacom->hdev, "String overflow while assembling device name");
> + }
> } else {
> snprintf(name, sizeof(name), "Wacom %s", product_name);
> }
> @@ -2242,7 +2244,9 @@ static void wacom_update_name(struct wacom *wacom, const char *suffix)
> if (name[strlen(name)-1] == ' ')
> name[strlen(name)-1] = '\0';
> } else {
> - strscpy(name, features->name, sizeof(name));
> + if (strscpy(name, features->name, sizeof(name)) < 0) {
> + hid_warn(wacom->hdev, "String overflow while assembling device name");
> + }
> }
>
> snprintf(wacom_wac->name, sizeof(wacom_wac->name), "%s%s",
> @@ -2500,8 +2504,10 @@ static void wacom_wireless_work(struct work_struct *work)
> goto fail;
> }
>
> - strscpy(wacom_wac->name, wacom_wac1->name,
> - sizeof(wacom_wac->name));
> + if (strscpy(wacom_wac->name, wacom_wac1->name,
> + sizeof(wacom_wac->name)) < 0) {
> + hid_warn(wacom->hdev, "String overflow while assembling device name");
> + }
> }
>
> return;
> --
> 2.40.0
>
Poking this thread again in case it got lost in the inbox...
Jason
---
Now instead of four in the eights place /
you’ve got three, ‘Cause you added one /
(That is to say, eight) to the two, /
But you can’t take seven from three, /
So you look at the sixty-fours....
