From: David Ahern dsahern@kernel.org
[ Upstream commit 61b91eb33a69c3be11b259c5ea484505cd79f883 ]
Gwangun Jung reported a slab-out-of-bounds access in fib_nh_match: fib_nh_match+0xf98/0x1130 linux-6.0-rc7/net/ipv4/fib_semantics.c:961 fib_table_delete+0x5f3/0xa40 linux-6.0-rc7/net/ipv4/fib_trie.c:1753 inet_rtm_delroute+0x2b3/0x380 linux-6.0-rc7/net/ipv4/fib_frontend.c:874
Separate nexthop objects are mutually exclusive with the legacy multipath spec. Fix fib_nh_match to return if the config for the to be deleted route contains a multipath spec while the fib_info is using a nexthop object.
Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects") Fixes: 6bf92d70e690 ("net: ipv4: fix route with nexthop object delete warning") Reported-by: Gwangun Jung exsociety@gmail.com Signed-off-by: David Ahern dsahern@kernel.org Reviewed-by: Ido Schimmel idosch@nvidia.com Tested-by: Ido Schimmel idosch@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: d5082d386eee ("ipv4: Fix route deletion when nexthop info is not specified") Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/fib_semantics.c | 8 ++++---- tools/testing/selftests/net/fib_nexthops.sh | 5 +++++ 2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 28da0443f3e9..31424172ff18 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -875,13 +875,13 @@ int fib_nh_match(struct fib_config *cfg, struct fib_info *fi, return 1; }
+ /* cannot match on nexthop object attributes */ + if (fi->nh) + return 1; + if (cfg->fc_oif || cfg->fc_gw_family) { struct fib_nh *nh;
- /* cannot match on nexthop object attributes */ - if (fi->nh) - return 1; - nh = fib_info_nh(fi, 0); if (cfg->fc_encap) { if (fib_encap_match(cfg->fc_encap_type, cfg->fc_encap, diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh index 7b154b61d108..28f5121fac44 100755 --- a/tools/testing/selftests/net/fib_nexthops.sh +++ b/tools/testing/selftests/net/fib_nexthops.sh @@ -597,6 +597,11 @@ ipv4_fcnal() log_test $rc 0 "Delete nexthop route warning" run_cmd "$IP route delete 172.16.101.1/32 nhid 12" run_cmd "$IP nexthop del id 12" + + run_cmd "$IP nexthop add id 21 via 172.16.1.6 dev veth1" + run_cmd "$IP ro add 172.16.101.0/24 nhid 21" + run_cmd "$IP ro del 172.16.101.0/24 nexthop via 172.16.1.7 dev veth1 nexthop via 172.16.1.8 dev veth1" + log_test $? 2 "Delete multipath route with only nh id based entry" }
ipv4_grp_fcnal()