From 3295582cd7a500f295b0585c36ef7a6032c77637 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sun, 4 Dec 2022 09:50:45 +0200 Subject: [PATCH] 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 Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 d38c8ca93ba09..be31eeacb0beb 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;