From: Victor Nogueira victor@mojatatu.com
[ Upstream commit 526f28bd0fbdc699cda31426928802650c1528e5 ]
There are cases where the device is adminstratively UP, but operationally down. For example, we have a physical device (Nvidia ConnectX-6 Dx, 25Gbps) who's cable was pulled out, here is its ip link output:
5: ens2f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000 link/ether b8:ce:f6:4b:68:35 brd ff:ff:ff:ff:ff:ff altname enp179s0f1np1
As you can see, it's administratively UP but operationally down. In this case, sending a packet to this port caused a nasty kernel hang (so nasty that we were unable to capture it). Aborting a transmit based on operational status (in addition to administrative status) fixes the issue.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Victor Nogueira victor@mojatatu.com v1->v2: Add fixes tag v2->v3: Remove blank line between tags + add change log, suggested by Leon Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/act_mirred.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index b87d2a1ee0b16..e3f28cb03f7e5 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -244,7 +244,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, goto out; }
- if (unlikely(!(dev->flags & IFF_UP))) { + if (unlikely(!(dev->flags & IFF_UP)) || !netif_carrier_ok(dev)) { net_notice_ratelimited("tc mirred to Houston: device %s is down\n", dev->name); goto out;