This is a note to let you know that I've just added the patch titled
mptcp: fix NULL pointer dereference on fastopen early fallback
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-fix-null-pointer-dereference-on-fastopen-early-fallback.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c0ff6f6da66a7791a32c0234388b1bdc00244917 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Tue, 11 Apr 2023 22:42:11 +0200
Subject: mptcp: fix NULL pointer dereference on fastopen early fallback
From: Paolo Abeni <pabeni@xxxxxxxxxx>
commit c0ff6f6da66a7791a32c0234388b1bdc00244917 upstream.
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@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mptcp/fastopen.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
--- 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;
Patches currently in stable-queue which might be from pabeni@xxxxxxxxxx are
queue-6.2/mptcp-stricter-state-check-in-mptcp_worker.patch
queue-6.2/mptcp-use-mptcp_schedule_work-instead-of-open-coding-it.patch
queue-6.2/net-phy-nxp-c45-tja11xx-add-remove-callback.patch
queue-6.2/mptcp-fix-null-pointer-dereference-on-fastopen-early-fallback.patch
queue-6.2/sctp-fix-a-potential-overflow-in-sctp_ifwdtsn_skip.patch
queue-6.2/selftests-mptcp-userspace-pm-uniform-verify-events.patch
queue-6.2/net-qrtr-fix-an-uninit-variable-access-bug-in-qrtr_t.patch
