From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794590807; b=KpOD0STAYmNs1pC6Z/QEgN9u2GcP/VaNAclzk2daN2tCwwKiyqtpHuEfOTqH3Lf7fxPK i0zhafz7Nhe2YMVwjHj8YER5knzekx5Jj6AULZibEVBnfQtqLZMU8bATvUwEvueHtHGn8 IgnX8MydSCzoEtbRt3hufUq3UAPlGJ8RNNmUu7PlMZ6tdrrzj/tmsfvIf3jcapVru/6nI /6gTeCFuFd6pLSaq/JNmOt0G/i4/MpVcL8BywaWQkd/75ViKpKwlTjw8cF8865zoib60Y UtpJYUsl6f4/7H7/on6vfaSlhF1qZ46lF/JI7PlJopsxvOTp/6Ifg9sbosx7VJKIquQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590807; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=Lt8l4oAIEI4okRjW4vasbYzAls1S1xpfK1uRXwiJfuw=; b=xQHxvaK2rNgJIDgeokeUqteW0d6T5s+QaZxAvj2wTJ18H1+kvzcQb4lUVbqoI+CO2cyq TSaC4ddsmXtiQ8trmsAnHEKqB2XHWAFhwaN71XtHag33QeoIZWa40YfeYbTbxrm2NAeKu kms3shX4dftWMl9iYdqqgOzYS2R2+3Ly11/VusfoOVBOp6CkK1bWvHQliPoxeH6MSYusV HP6X8ihiHAOBuIuNmnrA34PkkCPScGYz04j15E37xqqg8bUbTgHMRL2AJtG0QCzVAhR7F Ek+lpozSXRuwIaUfITQl+C9kcIhMckspuHfIRitc+2yE3saz37MtQaWLiM9UDCdEuDA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="xdd2bJ/Z"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5E3F7607D2E1; Fri, 13 Nov 2026 17:26:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=xdd2bJ/Z Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AC0C1F000C4; Fri, 13 Nov 2026 17:26:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590807; bh=Lt8l4oAIEI4okRjW4vasbYzAls1S1xpfK1uRXwiJfuw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=xdd2bJ/Zhw09BgayMU4zb9mctAvNHxEyJsE8gpj/jXZuTQR5Ne8koDwk0Vx+xhj1W rYtIq6T3FvMGrIoJ3HfArbrgdRF9mS80wlgaOpthfbIFOi7KG06ohNjkPMp6SA58XP voe0+uMurpBj7Lt7Z1UHSMsIsAejaOuMC99IdzPg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Siwei Zhang , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.12 009/670] Bluetooth: L2CAP: Reject signalling responses in invalid states Date: Fri, 13 Nov 2026 10:42:53 -0500 Message-ID: <20261113153811.498959187@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Siwei Zhang commit 6320736af7dcb90da6ee9fd651ecc11c564d45b7 upstream. Adjusted context as stable does not have the lockdep_assert_held() calls, and l2cap_get_chan_by_scid() still returns the channel locked, so l2cap_config_rsp() does not lock it again. A peer can send configuration messages while an incoming channel is in BT_CONNECT2, before the security or deferred accept gate has completed. A configuration response can then promote the channel to BT_CONNECTED. Configuration responses can also act on channels that are closing, and a late connection response can move a disconnecting channel back to BT_CONFIG. Accept connection responses only while waiting in BT_CONNECT. Answer configuration requests in BT_CONNECT2, but defer our own request until BT_CONFIG so configuration cannot complete before the gate. Ignore configuration responses outside BT_CONFIG and BT_CONNECTED, and only complete configuration in BT_CONFIG. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index d8c39a4306861..fa7124c32d91a 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4278,6 +4278,10 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn, l2cap_chan_lock(chan); + /* Ignore a late response after the channel has left BT_CONNECT. */ + if (chan->state != BT_CONNECT) + goto done; + switch (result) { case L2CAP_CR_SUCCESS: if (__l2cap_get_chan_by_dcid(conn, dcid)) { @@ -4307,6 +4311,7 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn, break; } +done: l2cap_chan_unlock(chan); l2cap_chan_put(chan); @@ -4439,7 +4444,13 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, goto unlock; } - if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { + /* A channel in BT_CONNECT2 has not passed security or userspace + * accept yet. Answer the peer's request, but hold our own until + * the channel reaches BT_CONFIG: the CONNECT2 -> CONFIG sites send + * it. Connected channels may also need to reconfigure. + */ + if ((chan->state == BT_CONFIG || chan->state == BT_CONNECTED) && + !test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) { u8 buf[64]; l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ, l2cap_build_conf_req(chan, buf, sizeof(buf)), buf); @@ -4487,6 +4498,10 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, if (!chan) return 0; + /* Connected channels may also receive reconfiguration responses. */ + if (chan->state != BT_CONFIG && chan->state != BT_CONNECTED) + goto done; + switch (result) { case L2CAP_CONF_SUCCESS: l2cap_conf_rfc_get(chan, rsp->data, len); @@ -4554,6 +4569,9 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) { set_default_fcs(chan); + if (chan->state != BT_CONFIG) + goto done; + if (chan->mode == L2CAP_MODE_ERTM || chan->mode == L2CAP_MODE_STREAMING) err = l2cap_ertm_init(chan); -- 2.53.0