[PATCH 5/5] [RFC] devlink: Fix uninitialized error code in devlink_fmsg_prepare_skb()

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Igor Konopko <igor.j.konopko@intel.com>,
	David Howells <dhowells@redhat.com>,
	"Mohit P . Tahiliani" <tahiliani@nitk.edu.in>,
	Takashi Sakamoto <o-takashi@sakamocchi.jp>,
	Eran Ben Elisha <eranbe@mellanox.com>,
	Matias Bjorling <mb@lightnvm.io>, Jiri Pirko <jiri@mellanox.com>,
	"David S . Miller" <davem@davemloft.net>,
	Jamal Hadi Salim <jhs@mojatatu.com>,
	Cong Wang <xiyou.wangcong@gmail.com>,
	Clemens Ladisch <clemens@ladisch.de>,
	Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	Joe Perches <joe@perches.com>, Arnd Bergmann <arnd@arndb.de>,
	Dan Carpenter <dan.carpenter@oracle.com>
Cc: linux-block@vger.kernel.org, netdev@vger.kernel.org,
	linux-afs@lists.infradead.org, alsa-devel@alsa-project.org,
	linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH 5/5] [RFC] devlink: Fix uninitialized error code in devlink_fmsg_prepare_skb()
Date: Tue, 28 May 2019 16:24:24 +0200	[thread overview]
Message-ID: <20190528142424.19626-6-geert@linux-m68k.org> (raw)
In-Reply-To: <20190528142424.19626-1-geert@linux-m68k.org>

With gcc 4.1:

    net/core/devlink.c: In function ‘devlink_fmsg_prepare_skb’:
    net/core/devlink.c:4325: warning: ‘err’ may be used uninitialized in this function

Indeed, if the list has less than *start entries, an uninitialized error
code will be returned.

Fix this by preinitializing err to zero.

Fixes: 1db64e8733f65381 ("devlink: Add devlink formatted message (fmsg) API")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
I don't know if this can really happen, and if this is the right fix.
Perhaps err should be initialized to some valid error code instead?
---
 net/core/devlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index d43bc52b8840d76b..91377e4eae9a43c1 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -4321,8 +4321,8 @@ devlink_fmsg_prepare_skb(struct devlink_fmsg *fmsg, struct sk_buff *skb,
 {
 	struct devlink_fmsg_item *item;
 	struct nlattr *fmsg_nlattr;
+	int err = 0;
 	int i = 0;
-	int err;
 
 	fmsg_nlattr = nla_nest_start_noflag(skb, DEVLINK_ATTR_FMSG);
 	if (!fmsg_nlattr)
-- 
2.17.1

