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Date:   Fri, 25 Sep 2020 18:51:34 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Kfir Itzhak <mastertheknife@gmail.com>,
        David Ahern <dsahern@kernel.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH 4.19 23/37] ipv4: Update exception handling for multipath
 routes via same device
Message-ID: <20200925165134.GA7253@duo.ucw.cz>
References: <20200925124720.972208530@linuxfoundation.org>
 <20200925124724.448531559@linuxfoundation.org>
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Hi!

> [ Upstream commit 2fbc6e89b2f1403189e624cabaf73e189c5e50c6 ]
>=20
> Kfir reported that pmtu exceptions are not created properly for
> deployments where multipath routes use the same device.

This is mismerged (in a way that does not affect functionality):


> @@ -779,6 +779,8 @@ static void __ip_do_redirect(struct rtab
>  			if (fib_lookup(net, fl4, &res, 0) =3D=3D 0) {
>  				struct fib_nh *nh =3D &FIB_RES_NH(res);
> =20
> +				fib_select_path(net, &res, fl4, skb);
> +				nh =3D &FIB_RES_NH(res);
>  				update_or_create_fnhe(nh, fl4->daddr, new_gw,
>  						0, false,

nh is assigned value that is never used. Mainline patch removes the
assignment (but variable has different type).

4.19 should delete the assignment, too.

Best regards,
								Pavel

Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index f60e28418ece..84de87b7eedc 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -777,7 +777,7 @@ static void __ip_do_redirect(struct rtable *rt, struct =
sk_buff *skb, struct flow
 			neigh_event_send(n, NULL);
 		} else {
 			if (fib_lookup(net, fl4, &res, 0) =3D=3D 0) {
-				struct fib_nh *nh =3D &FIB_RES_NH(res);
+				struct fib_nh *nh;
=20
 				fib_select_path(net, &res, fl4, skb);
 				nh =3D &FIB_RES_NH(res);


--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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