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| author | Guillaume Nault <g.nault@alphalink.fr> | 2017-08-25 16:51:43 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-28 11:34:58 -0700 |
| commit | 4e4b21da3acc68a7ea55f850cacc13706b7480e9 (patch) | |
| tree | 6ddf36276df7ea036ca7fe77b354af690f5cc7d0 /net/l2tp | |
| parent | 8c0e421525c9eb50d68e8f633f703ca31680b746 (diff) | |
| download | lwn-4e4b21da3acc68a7ea55f850cacc13706b7480e9.tar.gz lwn-4e4b21da3acc68a7ea55f850cacc13706b7480e9.zip | |
l2tp: hold tunnel while handling genl TUNNEL_GET commands
Use l2tp_tunnel_get() instead of l2tp_tunnel_find() so that we get
a reference on the tunnel, preventing l2tp_tunnel_destruct() from
freeing it from under us.
Also move l2tp_tunnel_get() below nlmsg_new() so that we only take
the reference when needed.
Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp')
| -rw-r--r-- | net/l2tp/l2tp_netlink.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index d61e75b4e619..ae5170e26281 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -444,34 +444,37 @@ static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info) if (!info->attrs[L2TP_ATTR_CONN_ID]) { ret = -EINVAL; - goto out; + goto err; } tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel == NULL) { - ret = -ENODEV; - goto out; - } - msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) { ret = -ENOMEM; - goto out; + goto err; + } + + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto err_nlmsg; } ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET); if (ret < 0) - goto err_out; + goto err_nlmsg_tunnel; + + l2tp_tunnel_dec_refcount(tunnel); return genlmsg_unicast(net, msg, info->snd_portid); -err_out: +err_nlmsg_tunnel: + l2tp_tunnel_dec_refcount(tunnel); +err_nlmsg: nlmsg_free(msg); - -out: +err: return ret; } |