| Message ID | 20220707115612.2760569-1-m.grzeschik@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
| Series | usb: gadget: uvc: fix changing interface name via configfs | expand |
Hi Michael, Thank you for the patch. On Thu, Jul 07, 2022 at 01:56:12PM +0200, Michael Grzeschik wrote: > 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 <m.grzeschik@pengutronix.de> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > 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 e5a6b6e36b3dd8..4303a3283ba0a3 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); \
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index e5a6b6e36b3dd8..4303a3283ba0a3 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); \
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 <m.grzeschik@pengutronix.de> --- drivers/usb/gadget/function/uvc_configfs.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)