diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2023-04-11 22:42:11 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-04-13 09:58:55 -0700 |
| commit | c0ff6f6da66a7791a32c0234388b1bdc00244917 (patch) | |
| tree | 497dbc31124fcf1c5548279c653fb401d371dd22 | |
| parent | d6a0443733434408f2cbd4c53fea6910599bab9e (diff) | |
| download | linux-c0ff6f6da66a7791a32c0234388b1bdc00244917.tar.gz | |
mptcp: fix NULL pointer dereference on fastopen early fallback
In case of early fallback to TCP, subflow_syn_recv_sock() deletes
the subflow context before returning the newly allocated sock to
the caller.
The fastopen path does not cope with the above unconditionally
dereferencing the subflow context.
Fixes: 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/mptcp/fastopen.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/mptcp/fastopen.c b/net/mptcp/fastopen.c index d237d142171c5a..bceaab8dd8e460 100644 --- a/net/mptcp/fastopen.c +++ b/net/mptcp/fastopen.c @@ -9,11 +9,18 @@ void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow, struct request_sock *req) { - struct sock *ssk = subflow->tcp_sock; - struct sock *sk = subflow->conn; + struct sock *sk, *ssk; struct sk_buff *skb; struct tcp_sock *tp; + /* on early fallback the subflow context is deleted by + * subflow_syn_recv_sock() + */ + if (!subflow) + return; + + ssk = subflow->tcp_sock; + sk = subflow->conn; tp = tcp_sk(ssk); subflow->is_mptfo = 1; |