From: Lee Jones Date: Wed, 13 Dec 2023 16:42:33 +0000 (+0000) Subject: usb: gadget: uvc: Replace snprintf() with the safer scnprintf() variant X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0d12c1cca7883620b1888ce4b892a9ed27bf3682;p=linux.git usb: gadget: uvc: Replace snprintf() with the safer scnprintf() variant There is a general misunderstanding amongst engineers that {v}snprintf() returns the length of the data *actually* encoded into the destination array. However, as per the C99 standard {v}snprintf() really returns the length of the data that *would have been* written if there were enough space for it. This misunderstanding has led to buffer-overruns in the past. It's generally considered safer to use the {v}scnprintf() variants in their place (or even sprintf() in simple cases). So let's do that. Link: https://lwn.net/Articles/69419/ Link: https://github.com/KSPP/linux/issues/105 Cc: Laurent Pinchart Cc: Daniel Scally Cc: Andrzej Pietrasiewicz Signed-off-by: Lee Jones Reviewed-by: Laurent Pinchart Link: https://lore.kernel.org/r/20231213164246.1021885-5-lee@kernel.org Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index 9bf0e985acfab..7e704b2bcfd1c 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -3414,7 +3414,7 @@ static ssize_t f_uvc_opts_string_##cname##_show(struct config_item *item,\ int result; \ \ mutex_lock(&opts->lock); \ - result = snprintf(page, sizeof(opts->aname), "%s", opts->aname);\ + result = scnprintf(page, sizeof(opts->aname), "%s", opts->aname);\ mutex_unlock(&opts->lock); \ \ return result; \