From: Luiz Augusto von Dentz luiz.von.dentz@intel.com

commit 15f02b91056253e8cdc592888f431da0731337b8 upstream

This adds the initial code for Enhanced Credit Based Mode which introduces a new socket mode called L2CAP_MODE_EXT_FLOWCTL, which for the most part work the same as L2CAP_MODE_LE_FLOWCTL but uses different PDUs to setup the connections and also works over BR/EDR.

Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Cc: stable@vger.kernel.org # 5.4.x [CC: backport to 5.4: make l2cap_sock_setsockopt_old suitable for BT_DBG line.] Signed-off-by: Cengiz Can cengiz.can@canonical.com --- include/net/bluetooth/l2cap.h | 4 + net/bluetooth/l2cap_core.c | 545 +++++++++++++++++++++++++++++++++- net/bluetooth/l2cap_sock.c | 24 +- 3 files changed, 553 insertions(+), 20 deletions(-)

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index b2046b02d11d..21744c30f546 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -290,6 +290,8 @@ struct l2cap_conn_rsp { #define L2CAP_CR_LE_ENCRYPTION 0x0008 #define L2CAP_CR_LE_INVALID_SCID 0x0009 #define L2CAP_CR_LE_SCID_IN_USE 0X000A +#define L2CAP_CR_LE_UNACCEPT_PARAMS 0X000B +#define L2CAP_CR_LE_INVALID_PARAMS 0X000C

/* connect/create channel status */ #define L2CAP_CS_NO_INFO 0x0000 @@ -926,6 +928,7 @@ void l2cap_cleanup_sockets(void); bool l2cap_is_socket(struct socket *sock);

void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan); +void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan); void __l2cap_connect_rsp_defer(struct l2cap_chan *chan);

int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm); @@ -935,6 +938,7 @@ struct l2cap_chan *l2cap_chan_create(void); void l2cap_chan_close(struct l2cap_chan *chan, int reason); int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *dst, u8 dst_type); +int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu); int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len); void l2cap_chan_busy(struct l2cap_chan *chan, int busy); int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator); diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index afa7fc55555e..d4d818f3caa7 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -568,6 +568,17 @@ static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits) skb_queue_head_init(&chan->tx_q); }

+static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits) +{ + l2cap_le_flowctl_init(chan, tx_credits); + + /* L2CAP implementations shall support a minimum MPS of 64 octets */ + if (chan->mps < L2CAP_ECRED_MIN_MPS) { + chan->mps = L2CAP_ECRED_MIN_MPS; + chan->rx_credits = (chan->imtu / chan->mps) + 1; + } +} + void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan) { BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn, @@ -674,6 +685,7 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err) break;

case L2CAP_MODE_LE_FLOWCTL: + case L2CAP_MODE_EXT_FLOWCTL: skb_queue_purge(&chan->tx_q); break;

@@ -740,6 +752,27 @@ static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan) &rsp); }

+static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan) +{ + struct l2cap_conn *conn = chan->conn; + struct l2cap_ecred_conn_rsp rsp; + u16 result; + + if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) + result = L2CAP_CR_LE_AUTHORIZATION; + else + result = L2CAP_CR_LE_BAD_PSM; + + l2cap_state_change(chan, BT_DISCONN); + + memset(&rsp, 0, sizeof(rsp)); + + rsp.result = cpu_to_le16(result); + + l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), + &rsp); +} + static void l2cap_chan_connect_reject(struct l2cap_chan *chan) { struct l2cap_conn *conn = chan->conn; @@ -785,8 +818,16 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason) if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { if (conn->hcon->type == ACL_LINK) l2cap_chan_connect_reject(chan); - else if (conn->hcon->type == LE_LINK) - l2cap_chan_le_connect_reject(chan); + else if (conn->hcon->type == LE_LINK) { + switch (chan->mode) { + case L2CAP_MODE_LE_FLOWCTL: + l2cap_chan_le_connect_reject(chan); + break; + case L2CAP_MODE_EXT_FLOWCTL: + l2cap_chan_ecred_connect_reject(chan); + break; + } + } }

l2cap_chan_del(chan, reason); @@ -1309,8 +1350,13 @@ static void l2cap_chan_ready(struct l2cap_chan *chan) chan->conf_state = 0; __clear_chan_timer(chan);

- if (chan->mode == L2CAP_MODE_LE_FLOWCTL && !chan->tx_credits) - chan->ops->suspend(chan); + switch (chan->mode) { + case L2CAP_MODE_LE_FLOWCTL: + case L2CAP_MODE_EXT_FLOWCTL: + if (!chan->tx_credits) + chan->ops->suspend(chan); + break; + }

chan->state = BT_CONNECTED;

@@ -1339,6 +1385,31 @@ static void l2cap_le_connect(struct l2cap_chan *chan) sizeof(req), &req); }

+static void l2cap_ecred_connect(struct l2cap_chan *chan) +{ + struct l2cap_conn *conn = chan->conn; + struct { + struct l2cap_ecred_conn_req req; + __le16 scid; + } __packed pdu; + + if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags)) + return; + + l2cap_ecred_init(chan, 0); + + pdu.req.psm = chan->psm; + pdu.req.mtu = cpu_to_le16(chan->imtu); + pdu.req.mps = cpu_to_le16(chan->mps); + pdu.req.credits = cpu_to_le16(chan->rx_credits); + pdu.scid = cpu_to_le16(chan->scid); + + chan->ident = l2cap_get_ident(conn); + + l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ, + sizeof(pdu), &pdu); +} + static void l2cap_le_start(struct l2cap_chan *chan) { struct l2cap_conn *conn = chan->conn; @@ -1351,8 +1422,12 @@ static void l2cap_le_start(struct l2cap_chan *chan) return; }

- if (chan->state == BT_CONNECT) - l2cap_le_connect(chan); + if (chan->state == BT_CONNECT) { + if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) + l2cap_ecred_connect(chan); + else + l2cap_le_connect(chan); + } }

static void l2cap_start_connection(struct l2cap_chan *chan) @@ -2540,6 +2615,7 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)

switch (chan->mode) { case L2CAP_MODE_LE_FLOWCTL: + case L2CAP_MODE_EXT_FLOWCTL: /* Check outgoing MTU */ if (len > chan->omtu) return -EMSGSIZE; @@ -3758,6 +3834,45 @@ void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan) &rsp); }

+void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan) +{ + struct { + struct l2cap_ecred_conn_rsp rsp; + __le16 dcid[5]; + } __packed pdu; + struct l2cap_conn *conn = chan->conn; + u16 ident = chan->ident; + int i = 0; + + if (!ident) + return; + + BT_DBG("chan %p ident %d", chan, ident); + + pdu.rsp.mtu = cpu_to_le16(chan->imtu); + pdu.rsp.mps = cpu_to_le16(chan->mps); + pdu.rsp.credits = cpu_to_le16(chan->rx_credits); + pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS); + + mutex_lock(&conn->chan_lock); + + list_for_each_entry(chan, &conn->chan_l, list) { + if (chan->ident != ident) + continue; + + /* Reset ident so only one response is sent */ + chan->ident = 0; + + /* Include all channels pending with the same ident */ + pdu.dcid[i++] = cpu_to_le16(chan->scid); + } + + mutex_unlock(&conn->chan_lock); + + l2cap_send_cmd(conn, ident, L2CAP_ECRED_CONN_RSP, + sizeof(pdu.rsp) + i * sizeof(__le16), &pdu); +} + void __l2cap_connect_rsp_defer(struct l2cap_chan *chan) { struct l2cap_conn_rsp rsp; @@ -5717,6 +5832,351 @@ static inline int l2cap_le_credits(struct l2cap_conn *conn, return 0; }

+static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, + struct l2cap_cmd_hdr *cmd, u16 cmd_len, + u8 *data) +{ + struct l2cap_ecred_conn_req *req = (void *) data; + struct { + struct l2cap_ecred_conn_rsp rsp; + __le16 dcid[5]; + } __packed pdu; + struct l2cap_chan *chan, *pchan; + u16 credits, mtu, mps; + __le16 psm; + u8 result, len = 0; + int i, num_scid; + bool defer = false; + + if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { + result = L2CAP_CR_LE_INVALID_PARAMS; + goto response; + } + + mtu = __le16_to_cpu(req->mtu); + mps = __le16_to_cpu(req->mps); + + if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) { + result = L2CAP_CR_LE_UNACCEPT_PARAMS; + goto response; + } + + psm = req->psm; + credits = 0; + + BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps); + + memset(&pdu, 0, sizeof(pdu)); + + /* 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); + if (!pchan) { + result = L2CAP_CR_LE_BAD_PSM; + goto response; + } + + mutex_lock(&conn->chan_lock); + l2cap_chan_lock(pchan); + + if (!smp_sufficient_security(conn->hcon, pchan->sec_level, + SMP_ALLOW_STK)) { + result = L2CAP_CR_LE_AUTHENTICATION; + goto unlock; + } + + result = L2CAP_CR_LE_SUCCESS; + cmd_len -= sizeof(req); + num_scid = cmd_len / sizeof(u16); + + for (i = 0; i < num_scid; i++) { + u16 scid = __le16_to_cpu(req->scid[i]); + + BT_DBG("scid[%d] 0x%4.4x", i, scid); + + pdu.dcid[i] = 0x0000; + len += sizeof(*pdu.dcid); + + /* Check for valid dynamic CID range */ + if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) { + result = L2CAP_CR_LE_INVALID_SCID; + continue; + } + + /* Check if we already have channel with that dcid */ + if (__l2cap_get_chan_by_dcid(conn, scid)) { + result = L2CAP_CR_LE_SCID_IN_USE; + continue; + } + + chan = pchan->ops->new_connection(pchan); + if (!chan) { + result = L2CAP_CR_LE_NO_MEM; + continue; + } + + bacpy(&chan->src, &conn->hcon->src); + bacpy(&chan->dst, &conn->hcon->dst); + chan->src_type = bdaddr_src_type(conn->hcon); + chan->dst_type = bdaddr_dst_type(conn->hcon); + chan->psm = psm; + chan->dcid = scid; + chan->omtu = mtu; + chan->remote_mps = mps; + + __l2cap_chan_add(conn, chan); + + l2cap_ecred_init(chan, __le16_to_cpu(req->credits)); + + /* Init response */ + if (!pdu.rsp.credits) { + pdu.rsp.mtu = cpu_to_le16(chan->imtu); + pdu.rsp.mps = cpu_to_le16(chan->mps); + pdu.rsp.credits = cpu_to_le16(chan->rx_credits); + } + + pdu.dcid[i] = cpu_to_le16(chan->scid); + + __set_chan_timer(chan, chan->ops->get_sndtimeo(chan)); + + chan->ident = cmd->ident; + + if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) { + l2cap_state_change(chan, BT_CONNECT2); + defer = true; + chan->ops->defer(chan); + } else { + l2cap_chan_ready(chan); + } + } + +unlock: + l2cap_chan_unlock(pchan); + mutex_unlock(&conn->chan_lock); + l2cap_chan_put(pchan); + +response: + pdu.rsp.result = cpu_to_le16(result); + + if (defer) + return 0; + + l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP, + sizeof(pdu.rsp) + len, &pdu); + + return 0; +} + +static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn, + struct l2cap_cmd_hdr *cmd, u16 cmd_len, + u8 *data) +{ + struct l2cap_ecred_conn_rsp *rsp = (void *) data; + struct hci_conn *hcon = conn->hcon; + u16 mtu, mps, credits, result; + struct l2cap_chan *chan; + int err = 0, sec_level; + int i = 0; + + if (cmd_len < sizeof(*rsp)) + return -EPROTO; + + mtu = __le16_to_cpu(rsp->mtu); + mps = __le16_to_cpu(rsp->mps); + credits = __le16_to_cpu(rsp->credits); + result = __le16_to_cpu(rsp->result); + + BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits, + result); + + mutex_lock(&conn->chan_lock); + + cmd_len -= sizeof(*rsp); + + list_for_each_entry(chan, &conn->chan_l, list) { + u16 dcid; + + if (chan->ident != cmd->ident || + chan->mode != L2CAP_MODE_EXT_FLOWCTL || + chan->state == BT_CONNECTED) + continue; + + l2cap_chan_lock(chan); + + /* Check that there is a dcid for each pending channel */ + if (cmd_len < sizeof(dcid)) { + l2cap_chan_del(chan, ECONNREFUSED); + l2cap_chan_unlock(chan); + continue; + } + + dcid = __le16_to_cpu(rsp->dcid[i++]); + cmd_len -= sizeof(u16); + + BT_DBG("dcid[%d] 0x%4.4x", i, dcid); + + /* Check if dcid is already in use */ + if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) { + /* If a device receives a + * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an + * already-assigned Destination CID, then both the + * original channel and the new channel shall be + * immediately discarded and not used. + */ + l2cap_chan_del(chan, ECONNREFUSED); + l2cap_chan_unlock(chan); + chan = __l2cap_get_chan_by_dcid(conn, dcid); + l2cap_chan_lock(chan); + l2cap_chan_del(chan, ECONNRESET); + l2cap_chan_unlock(chan); + continue; + } + + switch (result) { + case L2CAP_CR_LE_AUTHENTICATION: + case L2CAP_CR_LE_ENCRYPTION: + /* If we already have MITM protection we can't do + * anything. + */ + if (hcon->sec_level > BT_SECURITY_MEDIUM) { + l2cap_chan_del(chan, ECONNREFUSED); + break; + } + + sec_level = hcon->sec_level + 1; + if (chan->sec_level < sec_level) + chan->sec_level = sec_level; + + /* We'll need to send a new Connect Request */ + clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags); + + smp_conn_security(hcon, chan->sec_level); + break; + + case L2CAP_CR_LE_BAD_PSM: + l2cap_chan_del(chan, ECONNREFUSED); + break; + + default: + /* If dcid was not set it means channels was refused */ + if (!dcid) { + l2cap_chan_del(chan, ECONNREFUSED); + break; + } + + chan->ident = 0; + chan->dcid = dcid; + chan->omtu = mtu; + chan->remote_mps = mps; + chan->tx_credits = credits; + l2cap_chan_ready(chan); + break; + } + + l2cap_chan_unlock(chan); + } + + mutex_unlock(&conn->chan_lock); + + return err; +} + +static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn, + struct l2cap_cmd_hdr *cmd, u16 cmd_len, + u8 *data) +{ + struct l2cap_ecred_reconf_req *req = (void *) data; + struct l2cap_ecred_reconf_rsp rsp; + u16 mtu, mps, result; + struct l2cap_chan *chan; + int i, num_scid; + + if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) { + result = L2CAP_CR_LE_INVALID_PARAMS; + goto respond; + } + + mtu = __le16_to_cpu(req->mtu); + mps = __le16_to_cpu(req->mps); + + BT_DBG("mtu %u mps %u", mtu, mps); + + if (mtu < L2CAP_ECRED_MIN_MTU) { + result = L2CAP_RECONF_INVALID_MTU; + goto respond; + } + + if (mps < L2CAP_ECRED_MIN_MPS) { + result = L2CAP_RECONF_INVALID_MPS; + goto respond; + } + + cmd_len -= sizeof(*req); + num_scid = cmd_len / sizeof(u16); + result = L2CAP_RECONF_SUCCESS; + + for (i = 0; i < num_scid; i++) { + u16 scid; + + scid = __le16_to_cpu(req->scid[i]); + if (!scid) + return -EPROTO; + + chan = __l2cap_get_chan_by_dcid(conn, scid); + if (!chan) + continue; + + /* If the MTU value is decreased for any of the included + * channels, then the receiver shall disconnect all + * included channels. + */ + if (chan->omtu > mtu) { + BT_ERR("chan %p decreased MTU %u -> %u", chan, + chan->omtu, mtu); + result = L2CAP_RECONF_INVALID_MTU; + } + + chan->omtu = mtu; + chan->remote_mps = mps; + } + +respond: + rsp.result = cpu_to_le16(result); + + l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp), + &rsp); + + return 0; +} + +static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn, + struct l2cap_cmd_hdr *cmd, u16 cmd_len, + u8 *data) +{ + struct l2cap_chan *chan; + struct l2cap_ecred_conn_rsp *rsp = (void *) data; + u16 result; + + if (cmd_len < sizeof(*rsp)) + return -EPROTO; + + result = __le16_to_cpu(rsp->result); + + BT_DBG("result 0x%4.4x", rsp->result); + + if (!result) + return 0; + + list_for_each_entry(chan, &conn->chan_l, list) { + if (chan->ident != cmd->ident) + continue; + + l2cap_chan_del(chan, ECONNRESET); + } + + return 0; +} + static inline int l2cap_le_command_rej(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data) @@ -5772,6 +6232,22 @@ static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn, err = l2cap_le_credits(conn, cmd, cmd_len, data); break;

+ case L2CAP_ECRED_CONN_REQ: + err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data); + break; + + case L2CAP_ECRED_CONN_RSP: + err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data); + break; + + case L2CAP_ECRED_RECONF_REQ: + err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data); + break; + + case L2CAP_ECRED_RECONF_RSP: + err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data); + break; + case L2CAP_DISCONN_REQ: err = l2cap_disconnect_req(conn, cmd, cmd_len, data); break; @@ -6852,11 +7328,13 @@ static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) struct l2cap_le_credits pkt; u16 return_credits;

- return_credits = ((chan->imtu / chan->mps) + 1) - chan->rx_credits; + return_credits = (chan->imtu / chan->mps) + 1;

- if (!return_credits) + if (chan->rx_credits >= return_credits) return;

+ return_credits -= chan->rx_credits; + BT_DBG("chan %p returning %u credits to sender", chan, return_credits);

chan->rx_credits += return_credits; @@ -6869,7 +7347,7 @@ static void l2cap_chan_le_send_credits(struct l2cap_chan *chan) l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt); }

-static int l2cap_le_recv(struct l2cap_chan *chan, struct sk_buff *skb) +static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb) { int err;

@@ -6884,7 +7362,7 @@ static int l2cap_le_recv(struct l2cap_chan *chan, struct sk_buff *skb) return err; }

-static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) +static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) { int err;

@@ -6932,7 +7410,7 @@ static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) }

if (skb->len == sdu_len) - return l2cap_le_recv(chan, skb); + return l2cap_ecred_recv(chan, skb);

chan->sdu = skb; chan->sdu_len = sdu_len; @@ -6964,7 +7442,7 @@ static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) skb = NULL;

if (chan->sdu->len == chan->sdu_len) { - err = l2cap_le_recv(chan, chan->sdu); + err = l2cap_ecred_recv(chan, chan->sdu); if (!err) { chan->sdu = NULL; chan->sdu_last_frag = NULL; @@ -7026,7 +7504,8 @@ static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,

switch (chan->mode) { case L2CAP_MODE_LE_FLOWCTL: - if (l2cap_le_data_rcv(chan, skb) < 0) + case L2CAP_MODE_EXT_FLOWCTL: + if (l2cap_ecred_data_rcv(chan, skb) < 0) goto drop;

goto done; @@ -7254,8 +7733,8 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, struct hci_dev *hdev; int err;

- BT_DBG("%pMR -> %pMR (type %u) psm 0x%2.2x", &chan->src, dst, - dst_type, __le16_to_cpu(psm)); + BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src, + dst, dst_type, __le16_to_cpu(psm), chan->mode);

hdev = hci_get_route(dst, &chan->src, chan->src_type); if (!hdev) @@ -7283,6 +7762,7 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, case L2CAP_MODE_BASIC: break; case L2CAP_MODE_LE_FLOWCTL: + case L2CAP_MODE_EXT_FLOWCTL: break; case L2CAP_MODE_ERTM: case L2CAP_MODE_STREAMING: @@ -7408,6 +7888,38 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, } EXPORT_SYMBOL_GPL(l2cap_chan_connect);

+static void l2cap_ecred_reconfigure(struct l2cap_chan *chan) +{ + struct l2cap_conn *conn = chan->conn; + struct { + struct l2cap_ecred_reconf_req req; + __le16 scid; + } pdu; + + pdu.req.mtu = cpu_to_le16(chan->imtu); + pdu.req.mps = cpu_to_le16(chan->mps); + pdu.scid = cpu_to_le16(chan->scid); + + chan->ident = l2cap_get_ident(conn); + + l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ, + sizeof(pdu), &pdu); +} + +int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu) +{ + if (chan->imtu > mtu) + return -EINVAL; + + BT_DBG("chan %p mtu 0x%4.4x", chan, mtu); + + chan->imtu = mtu; + + l2cap_ecred_reconfigure(chan); + + return 0; +} + /* ---- L2CAP interface with lower layer (HCI) ---- */

int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr) @@ -7619,7 +8131,8 @@ static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt) else __set_chan_timer(chan, L2CAP_DISC_TIMEOUT); } else if (chan->state == BT_CONNECT2 && - chan->mode != L2CAP_MODE_LE_FLOWCTL) { + !(chan->mode == L2CAP_MODE_EXT_FLOWCTL || + chan->mode == L2CAP_MODE_LE_FLOWCTL)) { struct l2cap_conn_rsp rsp; __u16 res, stat;

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 08e9f332adad..703a6b961fd1 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -240,7 +240,7 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, return -EINVAL; }

- if (chan->psm && bdaddr_type_is_le(chan->src_type)) + if (chan->psm && bdaddr_type_is_le(chan->src_type) && !chan->mode) chan->mode = L2CAP_MODE_LE_FLOWCTL;

err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid), @@ -281,6 +281,7 @@ static int l2cap_sock_listen(struct socket *sock, int backlog) switch (chan->mode) { case L2CAP_MODE_BASIC: case L2CAP_MODE_LE_FLOWCTL: + case L2CAP_MODE_EXT_FLOWCTL: break; case L2CAP_MODE_ERTM: case L2CAP_MODE_STREAMING: @@ -449,6 +450,8 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, opts.max_tx = chan->max_tx; opts.txwin_size = chan->tx_win;

+ BT_DBG("mode 0x%2.2x", chan->mode); + len = min_t(unsigned int, len, sizeof(opts)); if (copy_to_user(optval, (char *) &opts, len)) err = -EFAULT; @@ -718,6 +721,9 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, break;

chan->mode = opts.mode; + + BT_DBG("mode 0x%2.2x", chan->mode); + chan->imtu = opts.imtu; chan->omtu = opts.omtu; chan->fcs = opts.fcs; @@ -950,7 +956,8 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, break; }

- if (sk->sk_state == BT_CONNECTED) { + if (chan->mode == L2CAP_MODE_LE_FLOWCTL && + sk->sk_state == BT_CONNECTED) { err = -EISCONN; break; } @@ -960,7 +967,12 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, break; }

- chan->imtu = opt; + if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && + sk->sk_state == BT_CONNECTED) + err = l2cap_chan_reconfigure(chan, opt); + else + chan->imtu = opt; + break;

default: @@ -1015,7 +1027,11 @@ static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg,

if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) { - if (bdaddr_type_is_le(pi->chan->src_type)) { + if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) { + sk->sk_state = BT_CONNECTED; + pi->chan->state = BT_CONNECTED; + __l2cap_ecred_conn_rsp_defer(pi->chan); + } if (bdaddr_type_is_le(pi->chan->src_type)) { sk->sk_state = BT_CONNECTED; pi->chan->state = BT_CONNECTED; __l2cap_le_connect_rsp_defer(pi->chan);

From: Luiz Augusto von Dentz luiz.von.dentz@intel.com

commit 711f8c3fb3db61897080468586b970c87c61d9e4 upstream

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 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 Cc: stable@vger.kernel.org # 5.4.x Signed-off-by: Cengiz Can cengiz.can@canonical.com --- net/bluetooth/l2cap_core.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index d4d818f3caa7..c4c25af1dbd5 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -5686,6 +5686,19 @@ 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); @@ -5864,6 +5877,18 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn, psm = req->psm; credits = 0;

+ /* 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));