[PATCH] ISDN: check for userspace copy faults

Most of the ISDN ->readstat() implementations needed to check
copy_to_user() and put_user() return values.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/drivers/isdn/pcbit/drv.c b/drivers/isdn/pcbit/drv.c
index 94f21486bb24..6ead5e1508b7 100644
--- a/drivers/isdn/pcbit/drv.c
+++ b/drivers/isdn/pcbit/drv.c
@@ -725,23 +725,27 @@ static int pcbit_stat(u_char __user *buf, int len, int driver, int channel)
 
         if (stat_st < stat_end)
         {
-                copy_to_user(buf, statbuf + stat_st, len);
+                if (copy_to_user(buf, statbuf + stat_st, len))
+                        return -EFAULT;
                 stat_st += len;    
         }
         else
         {
                 if (len > STATBUF_LEN - stat_st)
                 {
-                        copy_to_user(buf, statbuf + stat_st, 
-                                       STATBUF_LEN - stat_st);
-                        copy_to_user(buf, statbuf, 
-                                       len - (STATBUF_LEN - stat_st));
+                        if (copy_to_user(buf, statbuf + stat_st,
+                                       STATBUF_LEN - stat_st))
+                                return -EFAULT;
+                        if (copy_to_user(buf, statbuf,
+                                       len - (STATBUF_LEN - stat_st)))
+                                return -EFAULT;
 
                         stat_st = len - (STATBUF_LEN - stat_st);
                 }
                 else
                 {
-                        copy_to_user(buf, statbuf + stat_st, len);
+                        if (copy_to_user(buf, statbuf + stat_st, len))
+                                return -EFAULT;
 
                         stat_st += len;