[PATCH 4.4 50/63] usbip: fix usbip bind writing random string after command in match_busid

Greg Kroah-Hartman
2018-01-01T14:28:04Z

From: Juan Zea <juan.zea@qindel.com>

commit 544c4605acc5ae4afe7dd5914147947db182f2fb upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
tools/usb/usbip/src/utils.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- 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
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
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;