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swkim101gregkh
swkim101
authored and
gregkh
committed
Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
commit a5b862c upstream. l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 parent 7a4b16f commit d2b2f7d

7 files changed

Lines changed: 88 additions & 53 deletions

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‎include/net/bluetooth/hci.h‎

Lines changed: 9 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1666,6 +1666,15 @@ struct hci_cp_le_set_event_mask {
16661666
__u8 mask[8];
16671667
} __packed;
16681668

1669+
/* BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 4, Part E
1670+
* 7.8.2 LE Read Buffer Size command
1671+
* MAX_LE_MTU is 0xffff.
1672+
* 0 is also valid. It means that no dedicated LE Buffer exists.
1673+
* It should use the HCI_Read_Buffer_Size command and mtu is shared
1674+
* between BR/EDR and LE.
1675+
*/
1676+
#define HCI_MIN_LE_MTU 0x001b
1677+
16691678
#define HCI_OP_LE_READ_BUFFER_SIZE 0x2002
16701679
struct hci_rp_le_read_buffer_size {
16711680
__u8 status;

‎include/net/bluetooth/hci_core.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -706,6 +706,7 @@ struct hci_conn {
706706
__u16 handle;
707707
__u16 sync_handle;
708708
__u16 state;
709+
__u16 mtu;
709710
__u8 mode;
710711
__u8 type;
711712
__u8 role;

‎net/bluetooth/hci_conn.c‎

Lines changed: 51 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -909,11 +909,37 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
909909
{
910910
struct hci_conn *conn;
911911

912+
switch (type) {
913+
case ACL_LINK:
914+
if (!hdev->acl_mtu)
915+
return ERR_PTR(-ECONNREFUSED);
916+
break;
917+
case ISO_LINK:
918+
if (hdev->iso_mtu)
919+
/* Dedicated ISO Buffer exists */
920+
break;
921+
fallthrough;
922+
case LE_LINK:
923+
if (hdev->le_mtu && hdev->le_mtu < HCI_MIN_LE_MTU)
924+
return ERR_PTR(-ECONNREFUSED);
925+
if (!hdev->le_mtu && hdev->acl_mtu < HCI_MIN_LE_MTU)
926+
return ERR_PTR(-ECONNREFUSED);
927+
break;
928+
case SCO_LINK:
929+
case ESCO_LINK:
930+
if (!hdev->sco_pkts)
931+
/* Controller does not support SCO or eSCO over HCI */
932+
return ERR_PTR(-ECONNREFUSED);
933+
break;
934+
default:
935+
return ERR_PTR(-ECONNREFUSED);
936+
}
937+
912938
bt_dev_dbg(hdev, "dst %pMR handle 0x%4.4x", dst, handle);
913939

914940
conn = kzalloc(sizeof(*conn), GFP_KERNEL);
915941
if (!conn)
916-
return NULL;
942+
return ERR_PTR(-ENOMEM);
917943

918944
bacpy(&conn->dst, dst);
919945
bacpy(&conn->src, &hdev->bdaddr);
@@ -944,10 +970,12 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
944970
switch (type) {
945971
case ACL_LINK:
946972
conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
973+
conn->mtu = hdev->acl_mtu;
947974
break;
948975
case LE_LINK:
949976
/* conn->src should reflect the local identity address */
950977
hci_copy_identity_address(hdev, &conn->src, &conn->src_type);
978+
conn->mtu = hdev->le_mtu ? hdev->le_mtu : hdev->acl_mtu;
951979
break;
952980
case ISO_LINK:
953981
/* conn->src should reflect the local identity address */
@@ -959,16 +987,21 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
959987
else if (conn->role == HCI_ROLE_MASTER)
960988
conn->cleanup = cis_cleanup;
961989

990+
conn->mtu = hdev->iso_mtu ? hdev->iso_mtu :
991+
hdev->le_mtu ? hdev->le_mtu : hdev->acl_mtu;
962992
break;
963993
case SCO_LINK:
964994
if (lmp_esco_capable(hdev))
965995
conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
966996
(hdev->esco_type & EDR_ESCO_MASK);
967997
else
968998
conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
999+
1000+
conn->mtu = hdev->sco_mtu;
9691001
break;
9701002
case ESCO_LINK:
9711003
conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
1004+
conn->mtu = hdev->sco_mtu;
9721005
break;
9731006
}
9741007

@@ -1011,7 +1044,7 @@ struct hci_conn *hci_conn_add_unset(struct hci_dev *hdev, int type,
10111044

10121045
handle = hci_conn_hash_alloc_unset(hdev);
10131046
if (unlikely(handle < 0))
1014-
return NULL;
1047+
return ERR_PTR(-ECONNREFUSED);
10151048

10161049
return hci_conn_add(hdev, type, dst, role, handle);
10171050
}
@@ -1317,8 +1350,8 @@ struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
13171350
bacpy(&conn->dst, dst);
13181351
} else {
13191352
conn = hci_conn_add_unset(hdev, LE_LINK, dst, role);
1320-
if (!conn)
1321-
return ERR_PTR(-ENOMEM);
1353+
if (IS_ERR(conn))
1354+
return conn;
13221355
hci_conn_hold(conn);
13231356
conn->pending_sec_level = sec_level;
13241357
}
@@ -1494,8 +1527,8 @@ static struct hci_conn *hci_add_bis(struct hci_dev *hdev, bdaddr_t *dst,
14941527
return ERR_PTR(-EADDRINUSE);
14951528

14961529
conn = hci_conn_add_unset(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
1497-
if (!conn)
1498-
return ERR_PTR(-ENOMEM);
1530+
if (IS_ERR(conn))
1531+
return conn;
14991532

15001533
conn->state = BT_CONNECT;
15011534

@@ -1538,8 +1571,8 @@ struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
15381571
BT_DBG("requesting refresh of dst_addr");
15391572

15401573
conn = hci_conn_add_unset(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
1541-
if (!conn)
1542-
return ERR_PTR(-ENOMEM);
1574+
if (IS_ERR(conn))
1575+
return conn;
15431576

15441577
if (hci_explicit_conn_params_set(hdev, dst, dst_type) < 0) {
15451578
hci_conn_del(conn);
@@ -1586,8 +1619,8 @@ struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
15861619
acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
15871620
if (!acl) {
15881621
acl = hci_conn_add_unset(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
1589-
if (!acl)
1590-
return ERR_PTR(-ENOMEM);
1622+
if (IS_ERR(acl))
1623+
return acl;
15911624
}
15921625

15931626
hci_conn_hold(acl);
@@ -1655,9 +1688,9 @@ struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
16551688
sco = hci_conn_hash_lookup_ba(hdev, type, dst);
16561689
if (!sco) {
16571690
sco = hci_conn_add_unset(hdev, type, dst, HCI_ROLE_MASTER);
1658-
if (!sco) {
1691+
if (IS_ERR(sco)) {
16591692
hci_conn_drop(acl);
1660-
return ERR_PTR(-ENOMEM);
1693+
return sco;
16611694
}
16621695
}
16631696

@@ -1847,8 +1880,8 @@ struct hci_conn *hci_bind_cis(struct hci_dev *hdev, bdaddr_t *dst,
18471880
qos->ucast.cis);
18481881
if (!cis) {
18491882
cis = hci_conn_add_unset(hdev, ISO_LINK, dst, HCI_ROLE_MASTER);
1850-
if (!cis)
1851-
return ERR_PTR(-ENOMEM);
1883+
if (IS_ERR(cis))
1884+
return cis;
18521885
cis->cleanup = cis_cleanup;
18531886
cis->dst_type = dst_type;
18541887
cis->iso_qos.ucast.cig = BT_ISO_QOS_CIG_UNSET;
@@ -1983,14 +2016,8 @@ static void hci_iso_qos_setup(struct hci_dev *hdev, struct hci_conn *conn,
19832016
struct bt_iso_io_qos *qos, __u8 phy)
19842017
{
19852018
/* Only set MTU if PHY is enabled */
1986-
if (!qos->sdu && qos->phy) {
1987-
if (hdev->iso_mtu > 0)
1988-
qos->sdu = hdev->iso_mtu;
1989-
else if (hdev->le_mtu > 0)
1990-
qos->sdu = hdev->le_mtu;
1991-
else
1992-
qos->sdu = hdev->acl_mtu;
1993-
}
2019+
if (!qos->sdu && qos->phy)
2020+
qos->sdu = conn->mtu;
19942021

19952022
/* Use the same PHY as ACL if set to any */
19962023
if (qos->phy == BT_ISO_PHY_ANY)
@@ -2071,8 +2098,8 @@ struct hci_conn *hci_pa_create_sync(struct hci_dev *hdev, bdaddr_t *dst,
20712098
return ERR_PTR(-EBUSY);
20722099

20732100
conn = hci_conn_add_unset(hdev, ISO_LINK, dst, HCI_ROLE_SLAVE);
2074-
if (!conn)
2075-
return ERR_PTR(-ENOMEM);
2101+
if (IS_ERR(conn))
2102+
return conn;
20762103

20772104
conn->iso_qos = *qos;
20782105
conn->state = BT_LISTEN;

‎net/bluetooth/hci_event.c‎

Lines changed: 20 additions & 11 deletions
Original file line numberDiff line numberDiff line change
@@ -954,6 +954,9 @@ static u8 hci_cc_read_buffer_size(struct hci_dev *hdev, void *data,
954954
BT_DBG("%s acl mtu %d:%d sco mtu %d:%d", hdev->name, hdev->acl_mtu,
955955
hdev->acl_pkts, hdev->sco_mtu, hdev->sco_pkts);
956956

957+
if (!hdev->acl_mtu || !hdev->acl_pkts)
958+
return HCI_ERROR_INVALID_PARAMETERS;
959+
957960
return rp->status;
958961
}
959962

@@ -1263,6 +1266,9 @@ static u8 hci_cc_le_read_buffer_size(struct hci_dev *hdev, void *data,
12631266

12641267
BT_DBG("%s le mtu %d:%d", hdev->name, hdev->le_mtu, hdev->le_pkts);
12651268

1269+
if (hdev->le_mtu && hdev->le_mtu < HCI_MIN_LE_MTU)
1270+
return HCI_ERROR_INVALID_PARAMETERS;
1271+
12661272
return rp->status;
12671273
}
12681274

@@ -2342,8 +2348,8 @@ static void hci_cs_create_conn(struct hci_dev *hdev, __u8 status)
23422348
if (!conn) {
23432349
conn = hci_conn_add_unset(hdev, ACL_LINK, &cp->bdaddr,
23442350
HCI_ROLE_MASTER);
2345-
if (!conn)
2346-
bt_dev_err(hdev, "no memory for new connection");
2351+
if (IS_ERR(conn))
2352+
bt_dev_err(hdev, "connection err: %ld", PTR_ERR(conn));
23472353
}
23482354
}
23492355

@@ -3154,8 +3160,8 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, void *data,
31543160
BDADDR_BREDR)) {
31553161
conn = hci_conn_add_unset(hdev, ev->link_type,
31563162
&ev->bdaddr, HCI_ROLE_SLAVE);
3157-
if (!conn) {
3158-
bt_dev_err(hdev, "no memory for new conn");
3163+
if (IS_ERR(conn)) {
3164+
bt_dev_err(hdev, "connection err: %ld", PTR_ERR(conn));
31593165
goto unlock;
31603166
}
31613167
} else {
@@ -3343,8 +3349,8 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
33433349
if (!conn) {
33443350
conn = hci_conn_add_unset(hdev, ev->link_type, &ev->bdaddr,
33453351
HCI_ROLE_SLAVE);
3346-
if (!conn) {
3347-
bt_dev_err(hdev, "no memory for new connection");
3352+
if (IS_ERR(conn)) {
3353+
bt_dev_err(hdev, "connection err: %ld", PTR_ERR(conn));
33483354
goto unlock;
33493355
}
33503356
}
@@ -3821,6 +3827,9 @@ static u8 hci_cc_le_read_buffer_size_v2(struct hci_dev *hdev, void *data,
38213827
BT_DBG("%s acl mtu %d:%d iso mtu %d:%d", hdev->name, hdev->acl_mtu,
38223828
hdev->acl_pkts, hdev->iso_mtu, hdev->iso_pkts);
38233829

3830+
if (hdev->le_mtu && hdev->le_mtu < HCI_MIN_LE_MTU)
3831+
return HCI_ERROR_INVALID_PARAMETERS;
3832+
38243833
return rp->status;
38253834
}
38263835

@@ -5768,8 +5777,8 @@ static void le_conn_complete_evt(struct hci_dev *hdev, u8 status,
57685777
goto unlock;
57695778

57705779
conn = hci_conn_add_unset(hdev, LE_LINK, bdaddr, role);
5771-
if (!conn) {
5772-
bt_dev_err(hdev, "no memory for new connection");
5780+
if (IS_ERR(conn)) {
5781+
bt_dev_err(hdev, "connection err: %ld", PTR_ERR(conn));
57735782
goto unlock;
57745783
}
57755784

@@ -6898,7 +6907,7 @@ static void hci_le_cis_req_evt(struct hci_dev *hdev, void *data,
68986907
if (!cis) {
68996908
cis = hci_conn_add(hdev, ISO_LINK, &acl->dst, HCI_ROLE_SLAVE,
69006909
cis_handle);
6901-
if (!cis) {
6910+
if (IS_ERR(cis)) {
69026911
hci_le_reject_cis(hdev, ev->cis_handle);
69036912
goto unlock;
69046913
}
@@ -7007,7 +7016,7 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
70077016
if (!bis) {
70087017
bis = hci_conn_add(hdev, ISO_LINK, BDADDR_ANY,
70097018
HCI_ROLE_SLAVE, handle);
7010-
if (!bis)
7019+
if (IS_ERR(bis))
70117020
continue;
70127021
}
70137022

@@ -7079,7 +7088,7 @@ static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
70797088
pa_sync = hci_conn_add_unset(hdev, ISO_LINK, BDADDR_ANY,
70807089
HCI_ROLE_SLAVE);
70817090

7082-
if (!pa_sync)
7091+
if (IS_ERR(pa_sync))
70837092
goto unlock;
70847093

70857094
pa_sync->sync_handle = le16_to_cpu(ev->sync_handle);

‎net/bluetooth/iso.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1285,7 +1285,7 @@ static int iso_sock_sendmsg(struct socket *sock, struct msghdr *msg,
12851285
return -ENOTCONN;
12861286
}
12871287

1288-
mtu = iso_pi(sk)->conn->hcon->hdev->iso_mtu;
1288+
mtu = iso_pi(sk)->conn->hcon->mtu;
12891289

12901290
release_sock(sk);
12911291

‎net/bluetooth/l2cap_core.c‎

Lines changed: 3 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -6241,7 +6241,7 @@ static int l2cap_finish_move(struct l2cap_chan *chan)
62416241
BT_DBG("chan %p", chan);
62426242

62436243
chan->rx_state = L2CAP_RX_STATE_RECV;
6244-
chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6244+
chan->conn->mtu = chan->conn->hcon->mtu;
62456245

62466246
return l2cap_resegment(chan);
62476247
}
@@ -6308,7 +6308,7 @@ static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
63086308
*/
63096309
chan->next_tx_seq = control->reqseq;
63106310
chan->unacked_frames = 0;
6311-
chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6311+
chan->conn->mtu = chan->conn->hcon->mtu;
63126312

63136313
err = l2cap_resegment(chan);
63146314

@@ -6848,18 +6848,7 @@ static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
68486848

68496849
BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
68506850

6851-
switch (hcon->type) {
6852-
case LE_LINK:
6853-
if (hcon->hdev->le_mtu) {
6854-
conn->mtu = hcon->hdev->le_mtu;
6855-
break;
6856-
}
6857-
fallthrough;
6858-
default:
6859-
conn->mtu = hcon->hdev->acl_mtu;
6860-
break;
6861-
}
6862-
6851+
conn->mtu = hcon->mtu;
68636852
conn->feat_mask = 0;
68646853

68656854
conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;

‎net/bluetooth/sco.c‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -126,7 +126,6 @@ static void sco_sock_clear_timer(struct sock *sk)
126126
/* ---- SCO connections ---- */
127127
static struct sco_conn *sco_conn_add(struct hci_conn *hcon)
128128
{
129-
struct hci_dev *hdev = hcon->hdev;
130129
struct sco_conn *conn = hcon->sco_data;
131130

132131
if (conn) {
@@ -144,9 +143,10 @@ static struct sco_conn *sco_conn_add(struct hci_conn *hcon)
144143

145144
hcon->sco_data = conn;
146145
conn->hcon = hcon;
146+
conn->mtu = hcon->mtu;
147147

148-
if (hdev->sco_mtu > 0)
149-
conn->mtu = hdev->sco_mtu;
148+
if (hcon->mtu > 0)
149+
conn->mtu = hcon->mtu;
150150
else
151151
conn->mtu = 60;
152152

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