staging: usbip: fix potential segfault because of unchecked return value of strchr.

This doesn't happen with the usbip virtual hci module, but another
module wanting to interface with this user space code could cause a
seg-fault by sending data without newlines.

Signed-off-by: Christopher Harvey <charvey@matrox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/usbip/userspace/libsrc/vhci_driver.c b/drivers/staging/usbip/userspace/libsrc/vhci_driver.c
index 269787751b208170208c653ffd9ef14a3fe5935c..0958ba53e94ad77e50a840c1785c73c336b5b01d 100644 (file)
--- a/drivers/staging/usbip/userspace/libsrc/vhci_driver.c
+++ b/drivers/staging/usbip/userspace/libsrc/vhci_driver.c
@@ -59,7 +59,10 @@ static int parse_status(char *value)
 
 
        /* skip a header line */
-       c = strchr(value, '\n') + 1;
+       c = strchr(value, '\n');
+       if (!c)
+               return -1;
+       c++;
 
        while (*c != '\0') {
                int port, status, speed, devid;
@@ -109,7 +112,10 @@ static int parse_status(char *value)
 
 
                /* go to the next line */
-               c = strchr(c, '\n') + 1;
+               c = strchr(c, '\n');
+               if (!c)
+                       break;
+               c++;
        }
 
        dbg("exit");
@@ -264,11 +270,17 @@ static int get_nports(void)
            attr_status->method, attr_status->value);
 
        /* skip a header line */
-       c = strchr(attr_status->value, '\n') + 1;
+       c = strchr(attr_status->value, '\n');
+       if (!c)
+               return 0;
+       c++;
 
        while (*c != '\0') {
                /* go to the next line */
-               c = strchr(c, '\n') + 1;
+               c = strchr(c, '\n');
+               if (!c)
+                       return nports;
+               c++;
                nports += 1;
        }