From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Ahern <dsa@cumulusnetworks.com>
Subject: Re: [PATCH net] ipv4: initialize flowi4_flags before calling
 fib_lookup()
Date: Tue, 22 Mar 2016 15:02:56 -0600
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 <CAM_iQpV6srT84xa4y0WHrKG0mbO2xs=rnKKCx1XB9FtWusxCgw@mail.gmail.com>
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Cc: Lance Richardson <lrichard@redhat.com>,
	Linux Kernel Network Developers <netdev@vger.kernel.org>
To: Cong Wang <xiyou.wangcong@gmail.com>
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On 3/22/16 2:45 PM, Cong Wang wrote:
> @@ -1426,7 +1426,7 @@ int fib_table_lookup(struct fib_table *tb, const
> struct flowi4 *flp,
>                              nh->nh_flags & RTNH_F_LINKDOWN &&
>                              !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
>                                  continue;
> -                       if (!(flp->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
> +                       if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
>                                  if (flp->flowi4_oif &&
>                                      flp->flowi4_oif != nh->nh_oif)
>                                          continue;
>
> For me, it looks the bug was introduce by commit 35ebf65e851c6d9731abc6362b1.
>

Arguably yes since it added the function without initializing flags.

The commit I referenced (and even the VRF predecessor both of which 
originated in the v4.3) is the one introducing use of flow flags to the 
lookup. From a stable perspective going back to v4.3 is what matters.