This is a note to let you know that I've just added the patch titled
ipv4: Fix incorrect route flushing when table ID 0 is used
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv4-fix-incorrect-route-flushing-when-table-id-0-is.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cfd0d5e5b7af2976d3d6bc06078ed2cdffe9fd88
Author: Ido Schimmel <idosch@xxxxxxxxxx>
Date: Sun Dec 4 09:50:45 2022 +0200
ipv4: Fix incorrect route flushing when table ID 0 is used
[ Upstream commit c0d999348e01df03e0a7f550351f3907fabbf611 ]
Cited commit added the table ID to the FIB info structure, but did not
properly initialize it when table ID 0 is used. This can lead to a route
in the default VRF with a preferred source address not being flushed
when the address is deleted.
Consider the following example:
# ip address add dev dummy1 192.0.2.1/28
# ip address add dev dummy1 192.0.2.17/28
# ip route add 198.51.100.0/24 via 192.0.2.2 src 192.0.2.17 metric 100
# ip route add table 0 198.51.100.0/24 via 192.0.2.2 src 192.0.2.17 metric 200
# ip route show 198.51.100.0/24
198.51.100.0/24 via 192.0.2.2 dev dummy1 src 192.0.2.17 metric 100
198.51.100.0/24 via 192.0.2.2 dev dummy1 src 192.0.2.17 metric 200
Both routes are installed in the default VRF, but they are using two
different FIB info structures. One with a metric of 100 and table ID of
254 (main) and one with a metric of 200 and table ID of 0. Therefore,
when the preferred source address is deleted from the default VRF,
the second route is not flushed:
# ip address del dev dummy1 192.0.2.17/28
# ip route show 198.51.100.0/24
198.51.100.0/24 via 192.0.2.2 dev dummy1 src 192.0.2.17 metric 200
Fix by storing a table ID of 254 instead of 0 in the route configuration
structure.
Add a test case that fails before the fix:
# ./fib_tests.sh -t ipv4_del_addr
IPv4 delete address route tests
Regular FIB info
TEST: Route removed from VRF when source address deleted [ OK ]
TEST: Route in default VRF not removed [ OK ]
TEST: Route removed in default VRF when source address deleted [ OK ]
TEST: Route in VRF is not removed by address delete [ OK ]
Identical FIB info with different table ID
TEST: Route removed from VRF when source address deleted [ OK ]
TEST: Route in default VRF not removed [ OK ]
TEST: Route removed in default VRF when source address deleted [ OK ]
TEST: Route in VRF is not removed by address delete [ OK ]
Table ID 0
TEST: Route removed in default VRF when source address deleted [FAIL]
Tests passed: 8
Tests failed: 1
And passes after:
# ./fib_tests.sh -t ipv4_del_addr
IPv4 delete address route tests
Regular FIB info
TEST: Route removed from VRF when source address deleted [ OK ]
TEST: Route in default VRF not removed [ OK ]
TEST: Route removed in default VRF when source address deleted [ OK ]
TEST: Route in VRF is not removed by address delete [ OK ]
Identical FIB info with different table ID
TEST: Route removed from VRF when source address deleted [ OK ]
TEST: Route in default VRF not removed [ OK ]
TEST: Route removed in default VRF when source address deleted [ OK ]
TEST: Route in VRF is not removed by address delete [ OK ]
Table ID 0
TEST: Route removed in default VRF when source address deleted [ OK ]
Tests passed: 9
Tests failed: 0
Fixes: 5a56a0b3a45d ("net: Don't delete routes in different VRFs")
Reported-by: Donald Sharp <sharpd@xxxxxxxxxx>
Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index d38c8ca93ba0..be31eeacb0be 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -840,6 +840,9 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
return -EINVAL;
}
+ if (!cfg->fc_table)
+ cfg->fc_table = RT_TABLE_MAIN;
+
return 0;
errout:
return err;
