[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, 2 insertions, 1 deletions

diff --git a/drivers/isdn/capi/capidrv.c b/drivers/isdn/capi/capidrv.c
index d10c8b82e6aa..b6f9476c0501 100644
--- a/drivers/isdn/capi/capidrv.c
+++ b/drivers/isdn/capi/capidrv.c
@@ -1907,7 +1907,8 @@ static int if_readstat(u8 __user *buf, int len, int id, int channel)
         }
 
         for (p=buf, count=0; count < len; p++, count++) {
-                put_user(*card->q931_read++, p);
+                if (put_user(*card->q931_read++, p))
+                        return -EFAULT;
                 if (card->q931_read > card->q931_end)
                         card->q931_read = card->q931_buf;
         }