The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

711f8c3fb3db ("Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM") 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 711f8c3fb3db61897080468586b970c87c61d9e4 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz luiz.von.dentz@intel.com Date: Mon, 31 Oct 2022 16:10:32 -0700 Subject: [PATCH] Bluetooth: L2CAP: Fix accepting connection request for invalid SPSM MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

The Bluetooth spec states that the valid range for SPSM is from 0x0001-0x00ff so it is invalid to accept values outside of this range:

BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A page 1059: Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges

CVE: CVE-2022-42896 CC: stable@vger.kernel.org Reported-by: Tamás Koczka poprdi@google.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Reviewed-by: Tedd Ho-Jeong An tedd.an@intel.com

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 1fbe087d6ae4..3eee915fb245 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -5813,6 +5813,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn, BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm), scid, mtu, mps);

+ /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A + * page 1059: + * + * Valid range: 0x0001-0x00ff + * + * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges + */ + if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { + result = L2CAP_CR_LE_BAD_PSM; + chan = NULL; + goto response; + } + /* Check if we have socket listening on psm */ pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src, &conn->hcon->dst, LE_LINK); @@ -6001,6 +6014,18 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,

psm = req->psm;

+ /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A + * page 1059: + * + * Valid range: 0x0001-0x00ff + * + * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges + */ + if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) { + result = L2CAP_CR_LE_BAD_PSM; + goto response; + } + BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);

memset(&pdu, 0, sizeof(pdu));