linux-kernel - [PATCH 3.14 049/100] Bluetooth: Fix incorrect LE CoC PDU length restriction based on HCI MTU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20141028033502.814131823@linuxfoundation.org>
Date:	Tue, 28 Oct 2014 11:35:34 +0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Johan Hedberg <johan.hedberg@...el.com>,
	Marcel Holtmann <marcel@...tmann.org>
Subject: [PATCH 3.14 049/100] Bluetooth: Fix incorrect LE CoC PDU length restriction based on HCI MTU

3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hedberg <johan.hedberg@...el.com>

commit 72c6fb915ff2d30ae14053edee4f0d30019bad76 upstream.

The l2cap_create_le_flowctl_pdu() function that l2cap_segment_le_sdu()
calls is perfectly capable of doing packet fragmentation if given bigger
PDUs than the HCI buffers allow. Forcing the PDU length based on the HCI
MTU (conn->mtu) would therefore needlessly strict operation on hardware
with limited LE buffers (e.g. both Intel and Broadcom seem to have this
set to just 27 bytes).

This patch removes the restriction and makes it possible to send PDUs of
the full length that the remote MPS value allows.

Signed-off-by: Johan Hedberg <johan.hedberg@...el.com>
Signed-off-by: Marcel Holtmann <marcel@...tmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 net/bluetooth/l2cap_core.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2608,12 +2608,8 @@ static int l2cap_segment_le_sdu(struct l
 
 	BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
 
-	pdu_len = chan->conn->mtu - L2CAP_HDR_SIZE;
-
-	pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
-
 	sdu_len = len;
-	pdu_len -= L2CAP_SDULEN_SIZE;
+	pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
 
 	while (len > 0) {
 		if (len <= pdu_len)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/