From: Jesper Juhl <jesper.juhl@gmail.com>

In drivers/isdn/capi/kcapi.c::old_capi_manufacturer(), if the call to
get_capi_ctr_by_nr(ldef.contr); in line 823 returns NULL, then we'll be
dereferencing a NULL pointer in the very next line.

(Found by Coverity checker as bug #402)

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/isdn/capi/kcapi.c |    2 ++
 1 files changed, 2 insertions(+)

diff -puN drivers/isdn/capi/kcapi.c~isdn-guard-against-a-potential-null-pointer-dereference-in-old_capi_manufacturer drivers/isdn/capi/kcapi.c
--- a/drivers/isdn/capi/kcapi.c~isdn-guard-against-a-potential-null-pointer-dereference-in-old_capi_manufacturer
+++ a/drivers/isdn/capi/kcapi.c
@@ -821,6 +821,8 @@ static int old_capi_manufacturer(unsigne
 				return -EFAULT;
 		}
 		card = get_capi_ctr_by_nr(ldef.contr);
+		if (!card)
+			return -EINVAL;
 		card = capi_ctr_get(card);
 		if (!card)
 			return -ESRCH;
_