| Message ID | 20221006150842.9336-1-dsahern@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2,net] ipv4: Handle attempt to delete multipath route when fib_info contains an nh reference | expand |
On 10/6/22 9:08 AM, David Ahern wrote: > diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh > index d5a0dd548989..15556138de76 100755 > --- a/tools/testing/selftests/net/fib_nexthops.sh > +++ b/tools/testing/selftests/net/fib_nexthops.sh > @@ -1223,6 +1223,11 @@ 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 $? 1 "Delete multipath route with only nh id based entry" > } > > ipv4_grp_fcnal() Did not intend to add this chunk to v2; it was hanging around the branch. :-) The return code check is wrong - should be 2, not 1. I will send a v3 later today.
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 2dc97583d279..85fc4afec7fb 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -888,13 +888,13 @@ int fib_nh_match(struct net *net, 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(net, cfg->fc_encap_type, @@ -926,6 +926,10 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, if (!cfg->fc_mp) return 0; + /* multipath spec and nexthop id are mutually exclusive */ + if (fi->nh) + return 1; + rtnh = cfg->fc_mp; remaining = cfg->fc_mp_len; diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh index d5a0dd548989..15556138de76 100755 --- a/tools/testing/selftests/net/fib_nexthops.sh +++ b/tools/testing/selftests/net/fib_nexthops.sh @@ -1223,6 +1223,11 @@ 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 $? 1 "Delete multipath route with only nh id based entry" } ipv4_grp_fcnal()
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> --- v2: - moved the fi->nh check up and added second Fixes tag (Ido's comments) net/ipv4/fib_semantics.c | 12 ++++++++---- tools/testing/selftests/net/fib_nexthops.sh | 5 +++++ 2 files changed, 13 insertions(+), 4 deletions(-)