From fa34cd94fb01fcb8d79d91e009451b37692e94e5 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 30 Sep 2016 18:13:49 +0200 Subject: [PATCH] net: rtnl: avoid uninitialized data in IFLA_VF_VLAN_LIST handling With the newly added support for IFLA_VF_VLAN_LIST netlink messages, we get a warning about potential uninitialized variable use in the parsing of the user input when enabling the -Wmaybe-uninitialized warning: net/core/rtnetlink.c: In function 'do_setvfinfo': net/core/rtnetlink.c:1756:9: error: 'ivvl$' may be used uninitialized in this function [-Werror=maybe-uninitialized] I have not been able to prove whether it is possible to arrive in this code with an empty IFLA_VF_VLAN_LIST block, but if we do, then ndo_set_vf_vlan gets called with uninitialized arguments. This adds an explicit check for an empty list, making it obvious to the reader and the compiler that this cannot happen. Fixes: 79aab093a0b5 ("net: Update API for VF vlan protocol 802.1ad support") Signed-off-by: Arnd Bergmann Reviewed-by: Moshe Shemesh Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3ac8946bf244..b06d2f46b83e 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1753,6 +1753,9 @@ static int do_setvfinfo(struct net_device *dev, struct nlattr **tb) len++; } + if (len == 0) + return -EINVAL; + err = ops->ndo_set_vf_vlan(dev, ivvl[0]->vf, ivvl[0]->vlan, ivvl[0]->qos, ivvl[0]->vlan_proto); if (err < 0) -- 2.20.1