isdn: kcapi: avoid uninitialized data

gcc-7 points out that the AVMB1_ADDCARD ioctl results in an unintialized
value ending up in the cardnr parameter:

drivers/isdn/capi/kcapi.c: In function 'old_capi_manufacturer':
drivers/isdn/capi/kcapi.c:1042:24: error: 'cdef.cardnr' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   cparams.cardnr = cdef.cardnr;

This has been broken since before the start of the git history, so
either the value is not used for anything important, or the ioctl
command doesn't get called in practice.

Setting the cardnr to zero avoids the warning and makes sure
we have consistent behavior.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c
index 1dfd1085a04f87a016a2405e68200f9c09a2263e..9ca691d6c13b4d31cdb5b29221214f377a7d490a 100644 (file)
--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -1032,6 +1032,7 @@ static int old_capi_manufacturer(unsigned int cmd, void __user *data)
                                                     sizeof(avmb1_carddef))))
                                return -EFAULT;
                        cdef.cardtype = AVM_CARDTYPE_B1;
+                       cdef.cardnr = 0;
                } else {
                        if ((retval = copy_from_user(&cdef, data,
                                                     sizeof(avmb1_extcarddef))))