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authorMasahiro Fujiwara <fujiwara.masahiro@gmail.com>2020-10-27 14:48:46 +0300
committerJakub Kicinski <kuba@kernel.org>2020-10-29 19:43:21 +0300
commit51467431200b91682b89d31317e35dcbca1469ce (patch)
tree4d1576d6cd250eebf1dc9ea072a25f4ddbf0cfc0
parentd6535dca28859d8d9ef80894eb287b2ac35a32e8 (diff)
downloadlinux-51467431200b91682b89d31317e35dcbca1469ce.tar.xz
gtp: fix an use-before-init in gtp_newlink()
*_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 <fujiwara.masahiro@gmail.com> Link: https://lore.kernel.org/r/20201027114846.3924-1-fujiwara.masahiro@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--drivers/net/gtp.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 030a1a5afe05..dc668ed280b9 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -657,10 +657,6 @@ 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 {
@@ -671,12 +667,16 @@ 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);
@@ -687,11 +687,11 @@ 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;
}