ipv4: initialise the itag variable in __mkroute_input

the value of itag is a random value from stack, and may not be initiated by
fib_validate_source, which called fib_combine_itag if CONFIG_IP_ROUTE_CLASSID
is not set

This will make the cached dst uncertainty

Signed-off-by: Li RongQing <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index db1e0da871f40a2284d67bd48c0f21d772b923f3..5e676be3daeb19e5f48df5e767a66b83ac73b432 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1519,7 +1519,7 @@ static int __mkroute_input(struct sk_buff *skb,
        struct in_device *out_dev;
        unsigned int flags = 0;
        bool do_cache;
-       u32 itag;
+       u32 itag = 0;
 
        /* get a working reference to the output device */
        out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));