[PATCH] fix infoleak in rtnetlink

From: Kangjie Lu
Date: Tue May 03 2016 - 16:43:26 EST


The stack object âmapâ has a total size of 32 bytes. Its last 4
bytes are padding generated by compiler. These padding bytes are
not initialized and sent out via ânla_putâ.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxxxxx>
---
net/core/rtnetlink.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a75f7e9..65763c2 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1180,14 +1180,16 @@ static noinline_for_stack int rtnl_fill_vfinfo(struct sk_buff *skb,

static int rtnl_fill_link_ifmap(struct sk_buff *skb, struct net_device *dev)
{
- struct rtnl_link_ifmap map = {
- .mem_start = dev->mem_start,
- .mem_end = dev->mem_end,
- .base_addr = dev->base_addr,
- .irq = dev->irq,
- .dma = dev->dma,
- .port = dev->if_port,
- };
+ struct rtnl_link_ifmap map;
+
+ memset(&map, 0, sizeof(map));
+ map.mem_start = dev->mem_start;
+ map.mem_end = dev->mem_end;
+ map.base_addr = dev->base_addr;
+ map.irq = dev->irq;
+ map.dma = dev->dma;
+ map.port = dev->if_port;
+
if (nla_put(skb, IFLA_MAP, sizeof(map), &map))
return -EMSGSIZE;

--
1.9.1