From eb83f502adb036cd56c27e13b9ca3b2aabfa790b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?H=C3=A5kon=20Bugge?= <haakon.bugge@oracle.com>
Date: Wed, 12 Oct 2022 16:15:42 +0200
Subject: [PATCH 1/1] RDMA/cma: Use output interface for net_dev check
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Git-commit: eb83f502adb036cd56c27e13b9ca3b2aabfa790b
Patch-mainline: v6.1-rc4
References: git-fixes

Commit 27cfde795a96 ("RDMA/cma: Fix arguments order in net device
validation") swapped the src and dst addresses in the call to
validate_net_dev().

As a consequence, the test in validate_ipv4_net_dev() to see if the
net_dev is the right one, is incorrect for port 1 <-> 2 communication when
the ports are on the same sub-net. This is fixed by denoting the
flowi4_oif as the device instead of the incoming one.

The bug has not been observed using IPv6 addresses.

Fixes: 27cfde795a96 ("RDMA/cma: Fix arguments order in net device validation")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Link: https://lore.kernel.org/r/20221012141542.16925-1-haakon.bugge@oracle.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
---
 drivers/infiniband/core/cma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index cc2222b85c88..26d1772179b8 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1556,7 +1556,7 @@ static bool validate_ipv4_net_dev(struct net_device *net_dev,
 		return false;
 
 	memset(&fl4, 0, sizeof(fl4));
-	fl4.flowi4_iif = net_dev->ifindex;
+	fl4.flowi4_oif = net_dev->ifindex;
 	fl4.daddr = daddr;
 	fl4.saddr = saddr;
 
-- 
2.38.0.1.gee35aeee4b76