From 88b3bd57867606b98fc04be05b4aa299f1587780 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Date: Fri, 27 Jul 2018 18:15:46 +0200 Subject: [PATCH] ipv4: remove BUG_ON() from fib_compute_spec_dst [ Upstream commit 9fc12023d6f51551d6ca9ed7e02ecc19d79caf17 ] Remove BUG_ON() from fib_compute_spec_dst routine and check in_dev pointer during flowi4 data structure initialization. fib_compute_spec_dst routine can be run concurrently with device removal where ip_ptr net_device pointer is set to NULL. This can happen if userspace enables pkt info on UDP rx socket and the device is removed while traffic is flowing Fixes: 35ebf65e851c ("ipv4: Create and use fib_compute_spec_dst() helper") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv4/fib_frontend.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index db8a9840ffac..0b29649627a7 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -209,19 +209,19 @@ __be32 fib_compute_spec_dst(struct sk_buff *skb) return ip_hdr(skb)->daddr; in_dev = __in_dev_get_rcu(dev); - BUG_ON(!in_dev); net = dev_net(dev); scope = RT_SCOPE_UNIVERSE; if (!ipv4_is_zeronet(ip_hdr(skb)->saddr)) { + bool vmark = in_dev && IN_DEV_SRC_VMARK(in_dev); fl4.flowi4_oif = 0; fl4.flowi4_iif = LOOPBACK_IFINDEX; fl4.daddr = ip_hdr(skb)->saddr; fl4.saddr = 0; fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); fl4.flowi4_scope = scope; - fl4.flowi4_mark = IN_DEV_SRC_VMARK(in_dev) ? skb->mark : 0; + fl4.flowi4_mark = vmark ? skb->mark : 0; if (!fib_lookup(net, &fl4, &res)) return FIB_RES_PREFSRC(net, res); } else { -- GitLab