From 3d0dc539029b09fbd125444c16b11a8ed10b9d0f Mon Sep 17 00:00:00 2001 From: Michael Grzeschik Date: Thu, 7 Jul 2022 13:56:12 +0200 Subject: [PATCH] usb: gadget: uvc: fix changing interface name via configfs When setting the function name, it is always truncated by one char since snprintf is always including the null-termination in the len parameter. We use strscpy and fix the size setting to use len + 1 instead. Fixes: 324e4f85070f ("usb: gadget: uvc: allow changing interface name via configfs") Signed-off-by: Michael Grzeschik Link: https://lore.kernel.org/r/20220707115612.2760569-1-m.grzeschik@pengutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/uvc_configfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index e5a6b6e36b3d..4303a3283ba0 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -2371,6 +2371,7 @@ static ssize_t f_uvc_opts_string_##cname##_store(struct config_item *item,\ const char *page, size_t len) \ { \ struct f_uvc_opts *opts = to_f_uvc_opts(item); \ + int size = min(sizeof(opts->aname), len + 1); \ int ret = 0; \ \ mutex_lock(&opts->lock); \ @@ -2379,8 +2380,9 @@ static ssize_t f_uvc_opts_string_##cname##_store(struct config_item *item,\ goto end; \ } \ \ - ret = snprintf(opts->aname, min(sizeof(opts->aname), len), \ - "%s", page); \ + ret = strscpy(opts->aname, page, size); \ + if (ret == -E2BIG) \ + ret = size - 1; \ \ end: \ mutex_unlock(&opts->lock); \