From c997797401008403a8568c058f162c740175d750 Mon Sep 17 00:00:00 2001
From: Ido Schimmel <idosch@nvidia.com>
Date: Wed, 15 Mar 2023 14:40:09 +0200
Subject: [PATCH] ipv4: Fix incorrect table ID in IOCTL path
[ Upstream commit 8a2618e14f81604a9b6ad305d57e0c8da939cd65 ]
Commit f96a3d74554d ("ipv4: Fix incorrect route flushing when source
address is deleted") started to take the table ID field in the FIB info
structure into account when determining if two structures are identical
or not. This field is initialized using the 'fc_table' field in the
route configuration structure, which is not set when adding a route via
IOCTL.
The above can result in user space being able to install two identical
routes that only differ in the table ID field of their associated FIB
info.
Fix by initializing the table ID field in the route configuration
structure in the IOCTL path.
Before the fix:
# ip route add default via 192.0.2.2
# route add default gw 192.0.2.2
# ip -4 r show default
# default via 192.0.2.2 dev dummy10
# default via 192.0.2.2 dev dummy10
After the fix:
# ip route add default via 192.0.2.2
# route add default gw 192.0.2.2
SIOCADDRT: File exists
# ip -4 r show default
default via 192.0.2.2 dev dummy10
Audited the code paths to ensure there are no other paths that do not
properly initialize the route configuration structure when installing a
route.
Fixes: 5a56a0b3a45d ("net: Don't delete routes in different VRFs")
Fixes: f96a3d74554d ("ipv4: Fix incorrect route flushing when source address is deleted")
Reported-by: gaoxingwang <gaoxingwang1@huawei.com>
Link: https://lore.kernel.org/netdev/20230314144159.2354729-1-gaoxingwang1@huawei.com/
Tested-by: gaoxingwang <gaoxingwang1@huawei.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230315124009.4015212-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/fib_frontend.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 75c88d486327..c21d57f02c65 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -573,6 +573,9 @@ static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
cfg->fc_scope = RT_SCOPE_UNIVERSE;
}
+ if (!cfg->fc_table)
+ cfg->fc_table = RT_TABLE_MAIN;
+
if (cmd == SIOCDELRT)
return 0;