Patch "isdn: kcapi: avoid uninitialized data" has been added to the 4.4-stable tree

Patch "isdn: kcapi: avoid uninitialized data" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    isdn: kcapi: avoid uninitialized data

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     isdn-kcapi-avoid-uninitialized-data.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Dec 21 10:35:49 CET 2017
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 28 Mar 2017 12:11:07 +0200
Subject: isdn: kcapi: avoid uninitialized data

From: Arnd Bergmann <arnd@arndb.de>


[ Upstream commit af109a2cf6a9a6271fa420ae2d64d72d86c92b7d ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/isdn/capi/kcapi.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -1032,6 +1032,7 @@ static int old_capi_manufacturer(unsigne
 						     sizeof(avmb1_carddef))))
 				return -EFAULT;
 			cdef.cardtype = AVM_CARDTYPE_B1;
+			cdef.cardnr = 0;
 		} else {
 			if ((retval = copy_from_user(&cdef, data,
 						     sizeof(avmb1_extcarddef))))


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-4.4/hwmon-asus_atk0110-fix-uninitialized-data-access.patch
queue-4.4/arm-hide-finish_arch_post_lock_switch-from-modules.patch
queue-4.4/bna-avoid-writing-uninitialized-data-into-hw-registers.patch
queue-4.4/isdn-kcapi-avoid-uninitialized-data.patch