From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
Date: Mon, 16 Aug 2021 13:59:17 +0200
Subject: sch_cake: fix srchost/dsthost hashing mode
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Patch-mainline: v5.14-rc7
Git-commit: 86b9bbd332d0510679c7fedcee3e3bd278be5756
References: bsc#1176447
When adding support for using the skb->hash value as the flow hash in CAKE,
I accidentally introduced a logic error that broke the host-only isolation
modes of CAKE (srchost and dsthost keywords). Specifically, the flow_hash
variable should stay initialised to 0 in cake_hash() in pure host-based
hashing mode. Add a check for this before using the skb->hash value as
flow_hash.
Fixes: b0c19ed6088a ("sch_cake: Take advantage of skb->hash where appropriate")
Reported-by: Pete Heist <pete@heistp.net>
Tested-by: Pete Heist <pete@heistp.net>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/sch_cake.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -720,7 +720,7 @@ static u32 cake_hash(struct cake_tin_dat
skip_hash:
if (flow_override)
flow_hash = flow_override - 1;
- else if (use_skbhash)
+ else if (use_skbhash && (flow_mode & CAKE_FLOW_FLOWS))
flow_hash = skb->hash;
if (host_override) {
dsthost_hash = host_override - 1;