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authorPaolo Abeni <pabeni@redhat.com>2020-07-23 14:02:34 +0300
committerDavid S. Miller <davem@davemloft.net>2020-07-23 21:47:25 +0300
commitb7514694ed2952684a1e4fc44d83682140fd8cef (patch)
tree468b94431292db85adcd8e07cf1381e89e0b2d59 /net/mptcp/subflow.c
parentfa25e815d963115eb06036a8f6a50e724bc259e2 (diff)
downloadlinux-b7514694ed2952684a1e4fc44d83682140fd8cef.tar.xz
subflow: explicitly check for plain tcp rsk
When syncookie are in use, the TCP stack may feed into subflow_syn_recv_sock() plain TCP request sockets. We can't access mptcp_subflow_request_sock-specific fields on such sockets. Explicitly check the rsk ops to do safe accesses. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/subflow.c')
-rw-r--r--net/mptcp/subflow.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 7f3ef1840df5..3ef445f59556 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -415,7 +415,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
/* hopefully temporary handling for MP_JOIN+syncookie */
subflow_req = mptcp_subflow_rsk(req);
- fallback_is_fatal = subflow_req->mp_join;
+ fallback_is_fatal = tcp_rsk(req)->is_mptcp && subflow_req->mp_join;
fallback = !tcp_rsk(req)->is_mptcp;
if (fallback)
goto create_child;