diff options
| author | David Ahern <dsa@cumulusnetworks.com> | 2017-01-17 14:57:36 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-04 09:47:10 +0100 |
| commit | e9db042dca20f7b6c1969fa21b121dde01057a74 (patch) | |
| tree | 5b17c80683befc6b4da708c37ba772cf4a0aee78 /net/ipv4/fib_frontend.c | |
| parent | b335e65666610c456a5fed734cdd04ec84639a52 (diff) | |
lwtunnel: fix autoload of lwt modules
[ Upstream commit 9ed59592e3e379b2e9557dc1d9e9ec8fcbb33f16]
Trying to add an mpls encap route when the MPLS modules are not loaded
hangs. For example:
CONFIG_MPLS=y
CONFIG_NET_MPLS_GSO=m
CONFIG_MPLS_ROUTING=m
CONFIG_MPLS_IPTUNNEL=m
$ ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2
The ip command hangs:
root 880 826 0 21:25 pts/0 00:00:00 ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2
$ cat /proc/880/stack
[<ffffffff81065a9b>] call_usermodehelper_exec+0xd6/0x134
[<ffffffff81065efc>] __request_module+0x27b/0x30a
[<ffffffff814542f6>] lwtunnel_build_state+0xe4/0x178
[<ffffffff814aa1e4>] fib_create_info+0x47f/0xdd4
[<ffffffff814ae451>] fib_table_insert+0x90/0x41f
[<ffffffff814a8010>] inet_rtm_newroute+0x4b/0x52
...
modprobe is trying to load rtnl-lwt-MPLS:
root 881 5 0 21:25 ? 00:00:00 /sbin/modprobe -q -- rtnl-lwt-MPLS
and it hangs after loading mpls_router:
$ cat /proc/881/stack
[<ffffffff81441537>] rtnl_lock+0x12/0x14
[<ffffffff8142ca2a>] register_netdevice_notifier+0x16/0x179
[<ffffffffa0033025>] mpls_init+0x25/0x1000 [mpls_router]
[<ffffffff81000471>] do_one_initcall+0x8e/0x13f
[<ffffffff81119961>] do_init_module+0x5a/0x1e5
[<ffffffff810bd070>] load_module+0x13bd/0x17d6
...
The problem is that lwtunnel_build_state is called with rtnl lock
held preventing mpls_init from registering.
Given the potential references held by the time lwtunnel_build_state it
can not drop the rtnl lock to the load module. So, extract the module
loading code from lwtunnel_build_state into a new function to validate
the encap type. The new function is called while converting the user
request into a fib_config which is well before any table, device or
fib entries are examined.
Fixes: 745041e2aaf1 ("lwtunnel: autoload of lwt modules")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/fib_frontend.c')
| -rw-r--r-- | net/ipv4/fib_frontend.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 3e4f183fc241..5b03d7f3b255 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -46,6 +46,7 @@ #include <net/rtnetlink.h> #include <net/xfrm.h> #include <net/l3mdev.h> +#include <net/lwtunnel.h> #include <trace/events/fib.h> #ifndef CONFIG_IP_MULTIPLE_TABLES @@ -676,6 +677,10 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, cfg->fc_mx_len = nla_len(attr); break; case RTA_MULTIPATH: + err = lwtunnel_valid_encap_type_attr(nla_data(attr), + nla_len(attr)); + if (err < 0) + goto errout; cfg->fc_mp = nla_data(attr); cfg->fc_mp_len = nla_len(attr); break; @@ -690,6 +695,9 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, break; case RTA_ENCAP_TYPE: cfg->fc_encap_type = nla_get_u16(attr); + err = lwtunnel_valid_encap_type(cfg->fc_encap_type); + if (err < 0) + goto errout; break; } } |