From: Kai-Heng Feng <kai.heng.feng@canonical.com>
Date: Fri, 23 Mar 2018 19:26:35 +0000 (+0800)
Subject: usb: core: Copy parameter string correctly and remove superfluous null check
X-Git-Tag: v4.17-rc1~126^2~14
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a030501499b032bd218e1d01c07677bab6a0d53f;p=thirdparty%2Fkernel%2Flinux.git

usb: core: Copy parameter string correctly and remove superfluous null check

strsep() slices string, so the string gets copied by
param_set_copystring() at the end of quirks_param_set() is not the
original value.
Fix that by calling param_set_copystring() earlier.

The null check for val is unnecessary, the caller of quirks_param_set()
does not pass null string.
Remove the superfluous null check. This is found by Smatch.

Fixes: 027bd6cafd9a ("usb: core: Add "quirks" parameter for usbcore")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 6fb8d54332689..29e5f32b38df6 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -31,10 +31,15 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
 	u16 vid, pid;
 	u32 flags;
 	size_t i;
+	int err;
+
+	err = param_set_copystring(val, kp);
+	if (err)
+		return err;
 
 	mutex_lock(&quirk_mutex);
 
-	if (!val || !*val) {
+	if (!*val) {
 		quirk_count = 0;
 		kfree(quirk_list);
 		quirk_list = NULL;
@@ -133,7 +138,7 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
 unlock:
 	mutex_unlock(&quirk_mutex);
 
-	return param_set_copystring(val, kp);
+	return 0;
 }
 
 static const struct kernel_param_ops quirks_param_ops = {