[PATCH] usbip: fix usbip bind writing random string after command in match_busid

From: Juan Zea
Date: Fri Dec 15 2017 - 04:21:38 EST


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

diff --git a/tools/usb/usbip/src/utils.c b/tools/usb/usbip/src/utils.c
index 2b3d6d2..3d7b42e 100644
--- 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;
--
2.7.4