linux/net/bluetooth/amp.c
Gopal Tiwari e8bd76ede1 Bluetooth: Fix null pointer dereference in amp_read_loc_assoc_final_data
kernel panic trace looks like:

 #5 [ffffb9e08698fc80] do_page_fault at ffffffffb666e0d7
 #6 [ffffb9e08698fcb0] page_fault at ffffffffb70010fe
    [exception RIP: amp_read_loc_assoc_final_data+63]
    RIP: ffffffffc06ab54f  RSP: ffffb9e08698fd68  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: ffff8c8845a5a000  RCX: 0000000000000004
    RDX: 0000000000000000  RSI: ffff8c8b9153d000  RDI: ffff8c8845a5a000
    RBP: ffffb9e08698fe40   R8: 00000000000330e0   R9: ffffffffc0675c94
    R10: ffffb9e08698fe58  R11: 0000000000000001  R12: ffff8c8b9cbf6200
    R13: 0000000000000000  R14: 0000000000000000  R15: ffff8c8b2026da0b
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffb9e08698fda8] hci_event_packet at ffffffffc0676904 [bluetooth]
 #8 [ffffb9e08698fe50] hci_rx_work at ffffffffc06629ac [bluetooth]
 #9 [ffffb9e08698fe98] process_one_work at ffffffffb66f95e7

hcon->amp_mgr seems NULL triggered kernel panic in following line inside
function amp_read_loc_assoc_final_data

        set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);

Fixed by checking NULL for mgr.

Signed-off-by: Gopal Tiwari <gtiwari@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2021-02-02 17:23:14 +01:00

592 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
Copyright (c) 2011,2012 Intel Corp.
*/
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci.h>
#include <net/bluetooth/hci_core.h>
#include <crypto/hash.h>
#include "hci_request.h"
#include "a2mp.h"
#include "amp.h"
/* Remote AMP Controllers interface */
void amp_ctrl_get(struct amp_ctrl *ctrl)
{
BT_DBG("ctrl %p orig refcnt %d", ctrl,
kref_read(&ctrl->kref));
kref_get(&ctrl->kref);
}
static void amp_ctrl_destroy(struct kref *kref)
{
struct amp_ctrl *ctrl = container_of(kref, struct amp_ctrl, kref);
BT_DBG("ctrl %p", ctrl);
kfree(ctrl->assoc);
kfree(ctrl);
}
int amp_ctrl_put(struct amp_ctrl *ctrl)
{
BT_DBG("ctrl %p orig refcnt %d", ctrl,
kref_read(&ctrl->kref));
return kref_put(&ctrl->kref, &amp_ctrl_destroy);
}
struct amp_ctrl *amp_ctrl_add(struct amp_mgr *mgr, u8 id)
{
struct amp_ctrl *ctrl;
ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
if (!ctrl)
return NULL;
kref_init(&ctrl->kref);
ctrl->id = id;
mutex_lock(&mgr->amp_ctrls_lock);
list_add(&ctrl->list, &mgr->amp_ctrls);
mutex_unlock(&mgr->amp_ctrls_lock);
BT_DBG("mgr %p ctrl %p", mgr, ctrl);
return ctrl;
}
void amp_ctrl_list_flush(struct amp_mgr *mgr)
{
struct amp_ctrl *ctrl, *n;
BT_DBG("mgr %p", mgr);
mutex_lock(&mgr->amp_ctrls_lock);
list_for_each_entry_safe(ctrl, n, &mgr->amp_ctrls, list) {
list_del(&ctrl->list);
amp_ctrl_put(ctrl);
}
mutex_unlock(&mgr->amp_ctrls_lock);
}
struct amp_ctrl *amp_ctrl_lookup(struct amp_mgr *mgr, u8 id)
{
struct amp_ctrl *ctrl;
BT_DBG("mgr %p id %d", mgr, id);
mutex_lock(&mgr->amp_ctrls_lock);
list_for_each_entry(ctrl, &mgr->amp_ctrls, list) {
if (ctrl->id == id) {
amp_ctrl_get(ctrl);
mutex_unlock(&mgr->amp_ctrls_lock);
return ctrl;
}
}
mutex_unlock(&mgr->amp_ctrls_lock);
return NULL;
}
/* Physical Link interface */
static u8 __next_handle(struct amp_mgr *mgr)
{
if (++mgr->handle == 0)
mgr->handle = 1;
return mgr->handle;
}
struct hci_conn *phylink_add(struct hci_dev *hdev, struct amp_mgr *mgr,
u8 remote_id, bool out)
{
bdaddr_t *dst = &mgr->l2cap_conn->hcon->dst;
struct hci_conn *hcon;
u8 role = out ? HCI_ROLE_MASTER : HCI_ROLE_SLAVE;
hcon = hci_conn_add(hdev, AMP_LINK, dst, role);
if (!hcon)
return NULL;
BT_DBG("hcon %p dst %pMR", hcon, dst);
hcon->state = BT_CONNECT;
hcon->attempt++;
hcon->handle = __next_handle(mgr);
hcon->remote_id = remote_id;
hcon->amp_mgr = amp_mgr_get(mgr);
return hcon;
}
/* AMP crypto key generation interface */
static int hmac_sha256(u8 *key, u8 ksize, char *plaintext, u8 psize, u8 *output)
{
struct crypto_shash *tfm;
struct shash_desc *shash;
int ret;
if (!ksize)
return -EINVAL;
tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
if (IS_ERR(tfm)) {
BT_DBG("crypto_alloc_ahash failed: err %ld", PTR_ERR(tfm));
return PTR_ERR(tfm);
}
ret = crypto_shash_setkey(tfm, key, ksize);
if (ret) {
BT_DBG("crypto_ahash_setkey failed: err %d", ret);
goto failed;
}
shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
GFP_KERNEL);
if (!shash) {
ret = -ENOMEM;
goto failed;
}
shash->tfm = tfm;
ret = crypto_shash_digest(shash, plaintext, psize, output);
kfree(shash);
failed:
crypto_free_shash(tfm);
return ret;
}
int phylink_gen_key(struct hci_conn *conn, u8 *data, u8 *len, u8 *type)
{
struct hci_dev *hdev = conn->hdev;
struct link_key *key;
u8 keybuf[HCI_AMP_LINK_KEY_SIZE];
u8 gamp_key[HCI_AMP_LINK_KEY_SIZE];
int err;
if (!hci_conn_check_link_mode(conn))
return -EACCES;
BT_DBG("conn %p key_type %d", conn, conn->key_type);
/* Legacy key */
if (conn->key_type < 3) {
bt_dev_err(hdev, "legacy key type %d", conn->key_type);
return -EACCES;
}
*type = conn->key_type;
*len = HCI_AMP_LINK_KEY_SIZE;
key = hci_find_link_key(hdev, &conn->dst);
if (!key) {
BT_DBG("No Link key for conn %p dst %pMR", conn, &conn->dst);
return -EACCES;
}
/* BR/EDR Link Key concatenated together with itself */
memcpy(&keybuf[0], key->val, HCI_LINK_KEY_SIZE);
memcpy(&keybuf[HCI_LINK_KEY_SIZE], key->val, HCI_LINK_KEY_SIZE);
/* Derive Generic AMP Link Key (gamp) */
err = hmac_sha256(keybuf, HCI_AMP_LINK_KEY_SIZE, "gamp", 4, gamp_key);
if (err) {
bt_dev_err(hdev, "could not derive Generic AMP Key: err %d", err);
return err;
}
if (conn->key_type == HCI_LK_DEBUG_COMBINATION) {
BT_DBG("Use Generic AMP Key (gamp)");
memcpy(data, gamp_key, HCI_AMP_LINK_KEY_SIZE);
return err;
}
/* Derive Dedicated AMP Link Key: "802b" is 802.11 PAL keyID */
return hmac_sha256(gamp_key, HCI_AMP_LINK_KEY_SIZE, "802b", 4, data);
}
static void read_local_amp_assoc_complete(struct hci_dev *hdev, u8 status,
u16 opcode, struct sk_buff *skb)
{
struct hci_rp_read_local_amp_assoc *rp = (void *)skb->data;
struct amp_assoc *assoc = &hdev->loc_assoc;
size_t rem_len, frag_len;
BT_DBG("%s status 0x%2.2x", hdev->name, rp->status);
if (rp->status)
goto send_rsp;
frag_len = skb->len - sizeof(*rp);
rem_len = __le16_to_cpu(rp->rem_len);
if (rem_len > frag_len) {
BT_DBG("frag_len %zu rem_len %zu", frag_len, rem_len);
memcpy(assoc->data + assoc->offset, rp->frag, frag_len);
assoc->offset += frag_len;
/* Read other fragments */
amp_read_loc_assoc_frag(hdev, rp->phy_handle);
return;
}
memcpy(assoc->data + assoc->offset, rp->frag, rem_len);
assoc->len = assoc->offset + rem_len;
assoc->offset = 0;
send_rsp:
/* Send A2MP Rsp when all fragments are received */
a2mp_send_getampassoc_rsp(hdev, rp->status);
a2mp_send_create_phy_link_req(hdev, rp->status);
}
void amp_read_loc_assoc_frag(struct hci_dev *hdev, u8 phy_handle)
{
struct hci_cp_read_local_amp_assoc cp;
struct amp_assoc *loc_assoc = &hdev->loc_assoc;
struct hci_request req;
int err;
BT_DBG("%s handle %d", hdev->name, phy_handle);
cp.phy_handle = phy_handle;
cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
cp.len_so_far = cpu_to_le16(loc_assoc->offset);
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
if (err < 0)
a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
}
void amp_read_loc_assoc(struct hci_dev *hdev, struct amp_mgr *mgr)
{
struct hci_cp_read_local_amp_assoc cp;
struct hci_request req;
int err;
memset(&hdev->loc_assoc, 0, sizeof(struct amp_assoc));
memset(&cp, 0, sizeof(cp));
cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
set_bit(READ_LOC_AMP_ASSOC, &mgr->state);
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
if (err < 0)
a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
}
void amp_read_loc_assoc_final_data(struct hci_dev *hdev,
struct hci_conn *hcon)
{
struct hci_cp_read_local_amp_assoc cp;
struct amp_mgr *mgr = hcon->amp_mgr;
struct hci_request req;
int err;
if (!mgr)
return;
cp.phy_handle = hcon->handle;
cp.len_so_far = cpu_to_le16(0);
cp.max_len = cpu_to_le16(hdev->amp_assoc_size);
set_bit(READ_LOC_AMP_ASSOC_FINAL, &mgr->state);
/* Read Local AMP Assoc final link information data */
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_READ_LOCAL_AMP_ASSOC, sizeof(cp), &cp);
err = hci_req_run_skb(&req, read_local_amp_assoc_complete);
if (err < 0)
a2mp_send_getampassoc_rsp(hdev, A2MP_STATUS_INVALID_CTRL_ID);
}
static void write_remote_amp_assoc_complete(struct hci_dev *hdev, u8 status,
u16 opcode, struct sk_buff *skb)
{
struct hci_rp_write_remote_amp_assoc *rp = (void *)skb->data;
BT_DBG("%s status 0x%2.2x phy_handle 0x%2.2x",
hdev->name, rp->status, rp->phy_handle);
if (rp->status)
return;
amp_write_rem_assoc_continue(hdev, rp->phy_handle);
}
/* Write AMP Assoc data fragments, returns true with last fragment written*/
static bool amp_write_rem_assoc_frag(struct hci_dev *hdev,
struct hci_conn *hcon)
{
struct hci_cp_write_remote_amp_assoc *cp;
struct amp_mgr *mgr = hcon->amp_mgr;
struct amp_ctrl *ctrl;
struct hci_request req;
u16 frag_len, len;
ctrl = amp_ctrl_lookup(mgr, hcon->remote_id);
if (!ctrl)
return false;
if (!ctrl->assoc_rem_len) {
BT_DBG("all fragments are written");
ctrl->assoc_rem_len = ctrl->assoc_len;
ctrl->assoc_len_so_far = 0;
amp_ctrl_put(ctrl);
return true;
}
frag_len = min_t(u16, 248, ctrl->assoc_rem_len);
len = frag_len + sizeof(*cp);
cp = kzalloc(len, GFP_KERNEL);
if (!cp) {
amp_ctrl_put(ctrl);
return false;
}
BT_DBG("hcon %p ctrl %p frag_len %u assoc_len %u rem_len %u",
hcon, ctrl, frag_len, ctrl->assoc_len, ctrl->assoc_rem_len);
cp->phy_handle = hcon->handle;
cp->len_so_far = cpu_to_le16(ctrl->assoc_len_so_far);
cp->rem_len = cpu_to_le16(ctrl->assoc_rem_len);
memcpy(cp->frag, ctrl->assoc, frag_len);
ctrl->assoc_len_so_far += frag_len;
ctrl->assoc_rem_len -= frag_len;
amp_ctrl_put(ctrl);
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_WRITE_REMOTE_AMP_ASSOC, len, cp);
hci_req_run_skb(&req, write_remote_amp_assoc_complete);
kfree(cp);
return false;
}
void amp_write_rem_assoc_continue(struct hci_dev *hdev, u8 handle)
{
struct hci_conn *hcon;
BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
hcon = hci_conn_hash_lookup_handle(hdev, handle);
if (!hcon)
return;
/* Send A2MP create phylink rsp when all fragments are written */
if (amp_write_rem_assoc_frag(hdev, hcon))
a2mp_send_create_phy_link_rsp(hdev, 0);
}
void amp_write_remote_assoc(struct hci_dev *hdev, u8 handle)
{
struct hci_conn *hcon;
BT_DBG("%s phy handle 0x%2.2x", hdev->name, handle);
hcon = hci_conn_hash_lookup_handle(hdev, handle);
if (!hcon)
return;
BT_DBG("%s phy handle 0x%2.2x hcon %p", hdev->name, handle, hcon);
amp_write_rem_assoc_frag(hdev, hcon);
}
static void create_phylink_complete(struct hci_dev *hdev, u8 status,
u16 opcode)
{
struct hci_cp_create_phy_link *cp;
BT_DBG("%s status 0x%2.2x", hdev->name, status);
cp = hci_sent_cmd_data(hdev, HCI_OP_CREATE_PHY_LINK);
if (!cp)
return;
hci_dev_lock(hdev);
if (status) {
struct hci_conn *hcon;
hcon = hci_conn_hash_lookup_handle(hdev, cp->phy_handle);
if (hcon)
hci_conn_del(hcon);
} else {
amp_write_remote_assoc(hdev, cp->phy_handle);
}
hci_dev_unlock(hdev);
}
void amp_create_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
struct hci_conn *hcon)
{
struct hci_cp_create_phy_link cp;
struct hci_request req;
cp.phy_handle = hcon->handle;
BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
hcon->handle);
if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
&cp.key_type)) {
BT_DBG("Cannot create link key");
return;
}
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_CREATE_PHY_LINK, sizeof(cp), &cp);
hci_req_run(&req, create_phylink_complete);
}
static void accept_phylink_complete(struct hci_dev *hdev, u8 status,
u16 opcode)
{
struct hci_cp_accept_phy_link *cp;
BT_DBG("%s status 0x%2.2x", hdev->name, status);
if (status)
return;
cp = hci_sent_cmd_data(hdev, HCI_OP_ACCEPT_PHY_LINK);
if (!cp)
return;
amp_write_remote_assoc(hdev, cp->phy_handle);
}
void amp_accept_phylink(struct hci_dev *hdev, struct amp_mgr *mgr,
struct hci_conn *hcon)
{
struct hci_cp_accept_phy_link cp;
struct hci_request req;
cp.phy_handle = hcon->handle;
BT_DBG("%s hcon %p phy handle 0x%2.2x", hdev->name, hcon,
hcon->handle);
if (phylink_gen_key(mgr->l2cap_conn->hcon, cp.key, &cp.key_len,
&cp.key_type)) {
BT_DBG("Cannot create link key");
return;
}
hci_req_init(&req, hdev);
hci_req_add(&req, HCI_OP_ACCEPT_PHY_LINK, sizeof(cp), &cp);
hci_req_run(&req, accept_phylink_complete);
}
void amp_physical_cfm(struct hci_conn *bredr_hcon, struct hci_conn *hs_hcon)
{
struct hci_dev *bredr_hdev = hci_dev_hold(bredr_hcon->hdev);
struct amp_mgr *mgr = hs_hcon->amp_mgr;
struct l2cap_chan *bredr_chan;
BT_DBG("bredr_hcon %p hs_hcon %p mgr %p", bredr_hcon, hs_hcon, mgr);
if (!bredr_hdev || !mgr || !mgr->bredr_chan)
return;
bredr_chan = mgr->bredr_chan;
l2cap_chan_lock(bredr_chan);
set_bit(FLAG_EFS_ENABLE, &bredr_chan->flags);
bredr_chan->remote_amp_id = hs_hcon->remote_id;
bredr_chan->local_amp_id = hs_hcon->hdev->id;
bredr_chan->hs_hcon = hs_hcon;
bredr_chan->conn->mtu = hs_hcon->hdev->block_mtu;
__l2cap_physical_cfm(bredr_chan, 0);
l2cap_chan_unlock(bredr_chan);
hci_dev_put(bredr_hdev);
}
void amp_create_logical_link(struct l2cap_chan *chan)
{
struct hci_conn *hs_hcon = chan->hs_hcon;
struct hci_cp_create_accept_logical_link cp;
struct hci_dev *hdev;
BT_DBG("chan %p hs_hcon %p dst %pMR", chan, hs_hcon,
&chan->conn->hcon->dst);
if (!hs_hcon)
return;
hdev = hci_dev_hold(chan->hs_hcon->hdev);
if (!hdev)
return;
cp.phy_handle = hs_hcon->handle;
cp.tx_flow_spec.id = chan->local_id;
cp.tx_flow_spec.stype = chan->local_stype;
cp.tx_flow_spec.msdu = cpu_to_le16(chan->local_msdu);
cp.tx_flow_spec.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
cp.tx_flow_spec.acc_lat = cpu_to_le32(chan->local_acc_lat);
cp.tx_flow_spec.flush_to = cpu_to_le32(chan->local_flush_to);
cp.rx_flow_spec.id = chan->remote_id;
cp.rx_flow_spec.stype = chan->remote_stype;
cp.rx_flow_spec.msdu = cpu_to_le16(chan->remote_msdu);
cp.rx_flow_spec.sdu_itime = cpu_to_le32(chan->remote_sdu_itime);
cp.rx_flow_spec.acc_lat = cpu_to_le32(chan->remote_acc_lat);
cp.rx_flow_spec.flush_to = cpu_to_le32(chan->remote_flush_to);
if (hs_hcon->out)
hci_send_cmd(hdev, HCI_OP_CREATE_LOGICAL_LINK, sizeof(cp),
&cp);
else
hci_send_cmd(hdev, HCI_OP_ACCEPT_LOGICAL_LINK, sizeof(cp),
&cp);
hci_dev_put(hdev);
}
void amp_disconnect_logical_link(struct hci_chan *hchan)
{
struct hci_conn *hcon = hchan->conn;
struct hci_cp_disconn_logical_link cp;
if (hcon->state != BT_CONNECTED) {
BT_DBG("hchan %p not connected", hchan);
return;
}
cp.log_handle = cpu_to_le16(hchan->handle);
hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK, sizeof(cp), &cp);
}
void amp_destroy_logical_link(struct hci_chan *hchan, u8 reason)
{
BT_DBG("hchan %p", hchan);
hci_chan_del(hchan);
}