From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 644C6369990; Wed, 30 Sep 2026 15:47:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790783241; cv=none; b=OnMthB1rwvZBAU7VllIdSa2ynVwhivtnDJG//DWgUf4PYPLoo8iDYHLxu3fJ5YJqKamLQX8OnQJP8PqOvtehYqmjNu7GZjUatgoFMusxBbBBAobPFoP2ZD3K9EkzVx5hm4w6W/g03mY1AfKwZqw1VRB3DlDMXo/4kLti7WuoGJs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790783241; c=relaxed/simple; bh=eZzFWj/BoHjwfZFMO0nAzNw+j3gMX7wRbxwtn6DL0Gc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tAOiVC4f7OYn8BX42TTME2BcaYqZKm/lCJcwChyUrRTMfRgUXVDFhWxqwZOBqREsgf5AzjtUUzfmYBu9sBp3YQqYqrhafuygzE9rF+ng8Wuj7ICbhfzabRLF5BcXNlBTNN4lraJkmsIchXs0rXo829SfLNM07NGgRDFvkvWzCB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rHjDdSvv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rHjDdSvv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B9CE1F000FF; Wed, 30 Sep 2026 15:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790783237; bh=e6CwwEq+hKzM5T/ORF9njkgivWuQ7zb2pjoi+qfzcW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rHjDdSvvrqECWpZgEYYavwq07QIyGbCshwvmnLDfONMZMunCYvCR1ngHe0oHfWjSH nNNBGOuh+l0W0sx7/i5L5mcRcCr7SpB4P5Dql/yZ/PjPZ3sJsWQefS5pANqVGjTdlE qmJpgu+JtKoNPQiRCHKXhYPWq+lMtcnlKKOZFS+w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Matthieu Baerts , Florian Westphal , Mat Martineau , Jakub Kicinski , "Matthieu Baerts (NGI0)" Subject: [PATCH 5.10 328/595] mptcp: hold mptcp socket before calling tcp_done Date: Wed, 30 Sep 2026 17:23:41 +0200 Message-ID: <20260930152354.738773112@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152347.700140858@linuxfoundation.org> References: <20260930152347.700140858@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit ab82e996a1fa1b9ae514fa357d9ce8df62321157 upstream. When processing options from tcp reset path its possible that tcp_done(ssk) drops the last reference on the mptcp socket which results in use-after-free. Reviewed-by: Matthieu Baerts Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski Stable-dep-of: 2b0f561f21b2 ("mptcp: avoid unneeded actions on subflow reset") [ Conflicts in subflow.c, because commit 3ba14528684f ("mptcp: avoid setting TCP_CLOSE state twice") has already been backported and also had the same conflict: this commit here should have been backported first. Fixed now! ] Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman --- net/mptcp/subflow.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -279,11 +279,16 @@ void mptcp_subflow_reset(struct sock *ss struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); struct sock *sk = subflow->conn; + /* must hold: tcp_done() could drop last reference on parent */ + sock_hold(sk); + tcp_send_active_reset(ssk, GFP_ATOMIC); tcp_done(ssk); if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && schedule_work(&mptcp_sk(sk)->work)) - sock_hold(sk); + return; /* worker will put sk for us */ + + sock_put(sk); } static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)