3.16.61-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Guillaume Nault <[email protected]> commit de9bada5d389903f4faf33980e6a95a2911c7e6d upstream. The /proc/net/pppol2tp handlers (pppol2tp_seq_*()) iterate over all L2TPv2 tunnels, and rightfully expect that only PPP sessions can be found there. However, l2tp_netlink accepts creating Ethernet sessions regardless of the underlying tunnel version. This confuses pppol2tp_seq_session_show(), which expects that l2tp_session_priv() returns a pppol2tp_session structure. When the session is an Ethernet pseudo-wire, a struct l2tp_eth_sess is returned instead. This leads to invalid memory access when pppol2tp_session_get_sock() later tries to dereference ps->sk. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- net/l2tp/l2tp_netlink.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -460,6 +460,12 @@ static int l2tp_nl_cmd_session_create(st goto out_tunnel; } + /* L2TPv2 only accepts PPP pseudo-wires */ + if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) { + ret = -EPROTONOSUPPORT; + goto out_tunnel; + } + if (tunnel->version > 2) { if (info->attrs[L2TP_ATTR_OFFSET]) cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);
