usbip: fix usbip bind writing random string after command in match_busid

usbip bind writes commands followed by random string when writing to
match_busid attribute in sysfs, caused by using full variable size
instead of string length.

Signed-off-by: Juan Zea <juan.zea@qindel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/usb/usbip/src/utils.c b/tools/usb/usbip/src/utils.c
index 2b3d6d2350158b73a2597dc1a78ac007b6a3563c..3d7b42e7729941b1ca8f35fb7f6d10d4151a1a2f 100644 (file)
--- a/tools/usb/usbip/src/utils.c
+++ b/tools/usb/usbip/src/utils.c
@@ -30,6 +30,7 @@ int modify_match_busid(char *busid, int add)
        char command[SYSFS_BUS_ID_SIZE + 4];
        char match_busid_attr_path[SYSFS_PATH_MAX];
        int rc;
+       int cmd_size;
 
        snprintf(match_busid_attr_path, sizeof(match_busid_attr_path),
                 "%s/%s/%s/%s/%s/%s", SYSFS_MNT_PATH, SYSFS_BUS_NAME,
@@ -37,12 +38,14 @@ int modify_match_busid(char *busid, int add)
                 attr_name);
 
        if (add)
-               snprintf(command, SYSFS_BUS_ID_SIZE + 4, "add %s", busid);
+               cmd_size = snprintf(command, SYSFS_BUS_ID_SIZE + 4, "add %s",
+                                   busid);
        else
-               snprintf(command, SYSFS_BUS_ID_SIZE + 4, "del %s", busid);
+               cmd_size = snprintf(command, SYSFS_BUS_ID_SIZE + 4, "del %s",
+                                   busid);
 
        rc = write_sysfs_attribute(match_busid_attr_path, command,
-                                  sizeof(command));
+                                  cmd_size);
        if (rc < 0) {
                dbg("failed to write match_busid: %s", strerror(errno));
                return -1;