From: Yoshihiro Shimoda <[email protected]>

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: <[email protected]> # v4.12+
Reviewed-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Yoshihiro Shimoda <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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;


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