From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> commit 5dac665cf403967bb79a7aeb8c182a621fe617ff upstream. Since the role_store() uses strncmp(), it's possible to refer out-of-memory if the sysfs data size is smaller than strlen("host"). This patch fixes it by using sysfs_streq() instead of strncmp(). Fixes: cc995c9ec118 ("usb: gadget: udc: renesas_usb3: add support for usb role swap") Cc: <stable@xxxxxxxxxxxxxxx> # v4.12+ Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/udc/renesas_usb3.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -21,6 +21,7 @@ #include <linux/pm_runtime.h> #include <linux/sizes.h> #include <linux/slab.h> +#include <linux/string.h> #include <linux/sys_soc.h> #include <linux/uaccess.h> #include <linux/usb/ch9.h> @@ -2315,9 +2316,9 @@ static ssize_t role_store(struct device if (usb3->forced_b_device) return -EBUSY; - if (!strncmp(buf, "host", strlen("host"))) + if (sysfs_streq(buf, "host")) new_mode_is_host = true; - else if (!strncmp(buf, "peripheral", strlen("peripheral"))) + else if (sysfs_streq(buf, "peripheral")) new_mode_is_host = false; else return -EINVAL;