On Sat, 24 Oct 2020 15:42:33 +0000 Masahiro Fujiwara wrote: Looks good, minor nits: - is the time zone broken on your system? Looks like your email has arrived with the date far in the past, so the build systems have missed it. Could you double check the time on your system? The hash looks short, should be at lest 12 chars: Fixes: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") no need for braces around single statement I'd personally move the out_hashtable: label here and keep it, just for clarity. Otherwise reader has to double check that gtp_encap_disable() can be safely called before gtp_encap_enable(). Also gtp_encap_disable() could change in the future breaking this assumption.

*_pdp_find() from gtp_encap_recv() would trigger a crash when a peer sends GTP packets while creating new GTP device. RIP: 0010:gtp1_pdp_find.isra.0+0x68/0x90 [gtp] <SNIP> Call Trace: <IRQ> gtp_encap_recv+0xc2/0x2e0 [gtp] ? gtp1_pdp_find.isra.0+0x90/0x90 [gtp] udp_queue_rcv_one_skb+0x1fe/0x530 udp_queue_rcv_skb+0x40/0x1b0 udp_unicast_rcv_skb.isra.0+0x78/0x90 __udp4_lib_rcv+0x5af/0xc70 udp_rcv+0x1a/0x20 ip_protocol_deliver_rcu+0xc5/0x1b0 ip_local_deliver_finish+0x48/0x50 ip_local_deliver+0xe5/0xf0 ? ip_protocol_deliver_rcu+0x1b0/0x1b0 gtp_encap_enable() should be called after gtp_hastable_new() otherwise *_pdp_find() will access the uninitialized hash table. Fixes: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Signed-off-by: Masahiro Fujiwara &lt;fujiwara.masahiro(a)gmail.com&gt; --- v2: - leave out_hashtable: label for clarity (Jakub). - fix code and comment styles. drivers/net/gtp.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 8e47d0112e5d..07cb6d9495e8 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -663,10 +663,6 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, gtp = netdev_priv(dev); - err = gtp_encap_enable(gtp, data); - if (err < 0) - return err; - if (!data[IFLA_GTP_PDP_HASHSIZE]) { hashsize = 1024; } else { @@ -676,13 +672,17 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, } err = gtp_hashtable_new(gtp, hashsize); + if (err < 0) + return err; + + err = gtp_encap_enable(gtp, data); if (err < 0) goto out_encap; err = register_netdevice(dev); if (err < 0) { netdev_dbg(dev, "failed to register new netdev %d\n", err); - goto out_hashtable; + goto out_encap; } gn = net_generic(dev_net(dev), gtp_net_id); @@ -693,11 +693,11 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, return 0; +out_encap: + gtp_encap_disable(gtp); out_hashtable: kfree(gtp->addr_hash); kfree(gtp->tid_hash); -out_encap: - gtp_encap_disable(gtp); return err; } -- 2.24.3

*_pdp_find() from gtp_encap_recv() would trigger a crash when a peer sends GTP packets while creating new GTP device. RIP: 0010:gtp1_pdp_find.isra.0+0x68/0x90 [gtp] <SNIP> Call Trace: <IRQ> gtp_encap_recv+0xc2/0x2e0 [gtp] ? gtp1_pdp_find.isra.0+0x90/0x90 [gtp] udp_queue_rcv_one_skb+0x1fe/0x530 udp_queue_rcv_skb+0x40/0x1b0 udp_unicast_rcv_skb.isra.0+0x78/0x90 __udp4_lib_rcv+0x5af/0xc70 udp_rcv+0x1a/0x20 ip_protocol_deliver_rcu+0xc5/0x1b0 ip_local_deliver_finish+0x48/0x50 ip_local_deliver+0xe5/0xf0 ? ip_protocol_deliver_rcu+0x1b0/0x1b0 gtp_encap_enable() should be called after gtp_hastable_new() otherwise *_pdp_find() will access the uninitialized hash table. v2: - Leave out_hashtable: label for clarity (Jakub). - Fix code and comment styles. Fixes: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Signed-off-by: Masahiro Fujiwara &lt;fujiwara.masahiro(a)gmail.com&gt; --- v3: - Fix goto err label. drivers/net/gtp.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 8e47d0112e5d..10f910f8cbe5 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -663,10 +663,6 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, gtp = netdev_priv(dev); - err = gtp_encap_enable(gtp, data); - if (err < 0) - return err; - if (!data[IFLA_GTP_PDP_HASHSIZE]) { hashsize = 1024; } else { @@ -677,12 +673,16 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, err = gtp_hashtable_new(gtp, hashsize); if (err < 0) - goto out_encap; + return err; + + err = gtp_encap_enable(gtp, data); + if (err < 0) + goto out_hashtable; err = register_netdevice(dev); if (err < 0) { netdev_dbg(dev, "failed to register new netdev %d\n", err); - goto out_hashtable; + goto out_encap; } gn = net_generic(dev_net(dev), gtp_net_id); @@ -693,11 +693,11 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, return 0; +out_encap: + gtp_encap_disable(gtp); out_hashtable: kfree(gtp->addr_hash); kfree(gtp->tid_hash); -out_encap: - gtp_encap_disable(gtp); return err; } -- 2.24.3