Re: [PATCH] ipv4: fix the rcu race between free_fib_info and ip_route_output_slow
From: Eric Dumazet <hidden>
Date: 2012-05-23 06:43:42
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On Wed, 2012-05-23 at 08:37 +0200, Eric Dumazet wrote:
From: Eric Dumazet <edumazet@google.com>
quoted hunk ↗ jump to hunk
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index ffcb3b0..b56b91e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c@@ -2127,7 +2127,7 @@ static int __mkroute_input(struct sk_buff *skb, u32 itag; /* get a working reference to the output device */ - out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res)); + out_dev = __in_dev_get_rcu(rcu_dereference(FIB_RES_DEV(*res)));
This part might need additional fix (if FIB_RES_DEV(*res) is NULL), because __in_dev_get_rcu() could crash dereferencing NULL pointer.