linux/net/bluetooth/mgmt_util.c
Luiz Augusto von Dentz 6fe26f694c Bluetooth: MGMT: Protect mgmt_pending list with its own lock
This uses a mutex to protect from concurrent access of mgmt_pending
list which can cause crashes like:

==================================================================
BUG: KASAN: slab-use-after-free in hci_sock_get_channel+0x60/0x68 net/bluetooth/hci_sock.c:91
Read of size 2 at addr ffff0000c48885b2 by task syz.4.334/7318

CPU: 0 UID: 0 PID: 7318 Comm: syz.4.334 Not tainted 6.15.0-rc7-syzkaller-g187899f4124a #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xa8/0x254 mm/kasan/report.c:408
 print_report+0x68/0x84 mm/kasan/report.c:521
 kasan_report+0xb0/0x110 mm/kasan/report.c:634
 __asan_report_load2_noabort+0x20/0x2c mm/kasan/report_generic.c:379
 hci_sock_get_channel+0x60/0x68 net/bluetooth/hci_sock.c:91
 mgmt_pending_find+0x7c/0x140 net/bluetooth/mgmt_util.c:223
 pending_find net/bluetooth/mgmt.c:947 [inline]
 remove_adv_monitor+0x44/0x1a4 net/bluetooth/mgmt.c:5445
 hci_mgmt_cmd+0x780/0xc00 net/bluetooth/hci_sock.c:1712
 hci_sock_sendmsg+0x544/0xbb0 net/bluetooth/hci_sock.c:1832
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 sock_write_iter+0x25c/0x378 net/socket.c:1131
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x62c/0x97c fs/read_write.c:684
 ksys_write+0x120/0x210 fs/read_write.c:736
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:744
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Allocated by task 7037:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:562
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_noprof+0x2fc/0x4c8 mm/slub.c:4339
 kmalloc_noprof include/linux/slab.h:909 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2198
 sk_alloc+0x44/0x3ac net/core/sock.c:2254
 bt_sock_alloc+0x4c/0x300 net/bluetooth/af_bluetooth.c:148
 hci_sock_create+0xa8/0x194 net/bluetooth/hci_sock.c:2202
 bt_sock_create+0x14c/0x24c net/bluetooth/af_bluetooth.c:132
 __sock_create+0x43c/0x91c net/socket.c:1541
 sock_create net/socket.c:1599 [inline]
 __sys_socket_create net/socket.c:1636 [inline]
 __sys_socket+0xd4/0x1c0 net/socket.c:1683
 __do_sys_socket net/socket.c:1697 [inline]
 __se_sys_socket net/socket.c:1695 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1695
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Freed by task 6607:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x68/0x88 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2380 [inline]
 slab_free mm/slub.c:4642 [inline]
 kfree+0x17c/0x474 mm/slub.c:4841
 sk_prot_free net/core/sock.c:2237 [inline]
 __sk_destruct+0x4f4/0x760 net/core/sock.c:2332
 sk_destruct net/core/sock.c:2360 [inline]
 __sk_free+0x320/0x430 net/core/sock.c:2371
 sk_free+0x60/0xc8 net/core/sock.c:2382
 sock_put include/net/sock.h:1944 [inline]
 mgmt_pending_free+0x88/0x118 net/bluetooth/mgmt_util.c:290
 mgmt_pending_remove+0xec/0x104 net/bluetooth/mgmt_util.c:298
 mgmt_set_powered_complete+0x418/0x5cc net/bluetooth/mgmt.c:1355
 hci_cmd_sync_work+0x204/0x33c net/bluetooth/hci_sync.c:334
 process_one_work+0x7e8/0x156c kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3400
 kthread+0x5fc/0x75c kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

Fixes: a380b6cff1 ("Bluetooth: Add generic mgmt helper API")
Closes: https://syzkaller.appspot.com/bug?extid=0a7039d5d9986ff4ecec
Closes: https://syzkaller.appspot.com/bug?extid=cc0cc52e7f43dc9e6df1
Reported-by: syzbot+0a7039d5d9986ff4ecec@syzkaller.appspotmail.com
Tested-by: syzbot+0a7039d5d9986ff4ecec@syzkaller.appspotmail.com
Tested-by: syzbot+cc0cc52e7f43dc9e6df1@syzkaller.appspotmail.com
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-06-05 14:54:57 -04:00

395 lines
8.8 KiB
C

/*
BlueZ - Bluetooth protocol stack for Linux
Copyright (C) 2015 Intel Corporation
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation;
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
SOFTWARE IS DISCLAIMED.
*/
#include <linux/unaligned.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/hci_mon.h>
#include <net/bluetooth/mgmt.h>
#include "mgmt_util.h"
static struct sk_buff *create_monitor_ctrl_event(__le16 index, u32 cookie,
u16 opcode, u16 len, void *buf)
{
struct hci_mon_hdr *hdr;
struct sk_buff *skb;
skb = bt_skb_alloc(6 + len, GFP_ATOMIC);
if (!skb)
return NULL;
put_unaligned_le32(cookie, skb_put(skb, 4));
put_unaligned_le16(opcode, skb_put(skb, 2));
if (buf)
skb_put_data(skb, buf, len);
__net_timestamp(skb);
hdr = skb_push(skb, HCI_MON_HDR_SIZE);
hdr->opcode = cpu_to_le16(HCI_MON_CTRL_EVENT);
hdr->index = index;
hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
return skb;
}
struct sk_buff *mgmt_alloc_skb(struct hci_dev *hdev, u16 opcode,
unsigned int size)
{
struct sk_buff *skb;
skb = alloc_skb(sizeof(struct mgmt_hdr) + size, GFP_KERNEL);
if (!skb)
return skb;
skb_reserve(skb, sizeof(struct mgmt_hdr));
bt_cb(skb)->mgmt.hdev = hdev;
bt_cb(skb)->mgmt.opcode = opcode;
return skb;
}
int mgmt_send_event_skb(unsigned short channel, struct sk_buff *skb, int flag,
struct sock *skip_sk)
{
struct hci_dev *hdev;
struct mgmt_hdr *hdr;
int len;
if (!skb)
return -EINVAL;
len = skb->len;
hdev = bt_cb(skb)->mgmt.hdev;
/* Time stamp */
__net_timestamp(skb);
/* Send just the data, without headers, to the monitor */
if (channel == HCI_CHANNEL_CONTROL)
hci_send_monitor_ctrl_event(hdev, bt_cb(skb)->mgmt.opcode,
skb->data, skb->len,
skb_get_ktime(skb), flag, skip_sk);
hdr = skb_push(skb, sizeof(*hdr));
hdr->opcode = cpu_to_le16(bt_cb(skb)->mgmt.opcode);
if (hdev)
hdr->index = cpu_to_le16(hdev->id);
else
hdr->index = cpu_to_le16(MGMT_INDEX_NONE);
hdr->len = cpu_to_le16(len);
hci_send_to_channel(channel, skb, flag, skip_sk);
kfree_skb(skb);
return 0;
}
int mgmt_send_event(u16 event, struct hci_dev *hdev, unsigned short channel,
void *data, u16 data_len, int flag, struct sock *skip_sk)
{
struct sk_buff *skb;
skb = mgmt_alloc_skb(hdev, event, data_len);
if (!skb)
return -ENOMEM;
if (data)
skb_put_data(skb, data, data_len);
return mgmt_send_event_skb(channel, skb, flag, skip_sk);
}
int mgmt_cmd_status(struct sock *sk, u16 index, u16 cmd, u8 status)
{
struct sk_buff *skb, *mskb;
struct mgmt_hdr *hdr;
struct mgmt_ev_cmd_status *ev;
int err;
BT_DBG("sock %p, index %u, cmd %u, status %u", sk, index, cmd, status);
skb = alloc_skb(sizeof(*hdr) + sizeof(*ev), GFP_KERNEL);
if (!skb)
return -ENOMEM;
hdr = skb_put(skb, sizeof(*hdr));
hdr->opcode = cpu_to_le16(MGMT_EV_CMD_STATUS);
hdr->index = cpu_to_le16(index);
hdr->len = cpu_to_le16(sizeof(*ev));
ev = skb_put(skb, sizeof(*ev));
ev->status = status;
ev->opcode = cpu_to_le16(cmd);
mskb = create_monitor_ctrl_event(hdr->index, hci_sock_get_cookie(sk),
MGMT_EV_CMD_STATUS, sizeof(*ev), ev);
if (mskb)
skb->tstamp = mskb->tstamp;
else
__net_timestamp(skb);
err = sock_queue_rcv_skb(sk, skb);
if (err < 0)
kfree_skb(skb);
if (mskb) {
hci_send_to_channel(HCI_CHANNEL_MONITOR, mskb,
HCI_SOCK_TRUSTED, NULL);
kfree_skb(mskb);
}
return err;
}
int mgmt_cmd_complete(struct sock *sk, u16 index, u16 cmd, u8 status,
void *rp, size_t rp_len)
{
struct sk_buff *skb, *mskb;
struct mgmt_hdr *hdr;
struct mgmt_ev_cmd_complete *ev;
int err;
BT_DBG("sock %p", sk);
skb = alloc_skb(sizeof(*hdr) + sizeof(*ev) + rp_len, GFP_KERNEL);
if (!skb)
return -ENOMEM;
hdr = skb_put(skb, sizeof(*hdr));
hdr->opcode = cpu_to_le16(MGMT_EV_CMD_COMPLETE);
hdr->index = cpu_to_le16(index);
hdr->len = cpu_to_le16(sizeof(*ev) + rp_len);
ev = skb_put(skb, sizeof(*ev) + rp_len);
ev->opcode = cpu_to_le16(cmd);
ev->status = status;
if (rp)
memcpy(ev->data, rp, rp_len);
mskb = create_monitor_ctrl_event(hdr->index, hci_sock_get_cookie(sk),
MGMT_EV_CMD_COMPLETE,
sizeof(*ev) + rp_len, ev);
if (mskb)
skb->tstamp = mskb->tstamp;
else
__net_timestamp(skb);
err = sock_queue_rcv_skb(sk, skb);
if (err < 0)
kfree_skb(skb);
if (mskb) {
hci_send_to_channel(HCI_CHANNEL_MONITOR, mskb,
HCI_SOCK_TRUSTED, NULL);
kfree_skb(mskb);
}
return err;
}
struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
struct hci_dev *hdev)
{
struct mgmt_pending_cmd *cmd, *tmp;
mutex_lock(&hdev->mgmt_pending_lock);
list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
if (hci_sock_get_channel(cmd->sk) != channel)
continue;
if (cmd->opcode == opcode) {
mutex_unlock(&hdev->mgmt_pending_lock);
return cmd;
}
}
mutex_unlock(&hdev->mgmt_pending_lock);
return NULL;
}
void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
void *data)
{
struct mgmt_pending_cmd *cmd, *tmp;
mutex_lock(&hdev->mgmt_pending_lock);
list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
if (opcode > 0 && cmd->opcode != opcode)
continue;
if (remove)
list_del(&cmd->list);
cb(cmd, data);
if (remove)
mgmt_pending_free(cmd);
}
mutex_unlock(&hdev->mgmt_pending_lock);
}
struct mgmt_pending_cmd *mgmt_pending_new(struct sock *sk, u16 opcode,
struct hci_dev *hdev,
void *data, u16 len)
{
struct mgmt_pending_cmd *cmd;
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (!cmd)
return NULL;
cmd->opcode = opcode;
cmd->hdev = hdev;
cmd->param = kmemdup(data, len, GFP_KERNEL);
if (!cmd->param) {
kfree(cmd);
return NULL;
}
cmd->param_len = len;
cmd->sk = sk;
sock_hold(sk);
return cmd;
}
struct mgmt_pending_cmd *mgmt_pending_add(struct sock *sk, u16 opcode,
struct hci_dev *hdev,
void *data, u16 len)
{
struct mgmt_pending_cmd *cmd;
cmd = mgmt_pending_new(sk, opcode, hdev, data, len);
if (!cmd)
return NULL;
mutex_lock(&hdev->mgmt_pending_lock);
list_add_tail(&cmd->list, &hdev->mgmt_pending);
mutex_unlock(&hdev->mgmt_pending_lock);
return cmd;
}
void mgmt_pending_free(struct mgmt_pending_cmd *cmd)
{
sock_put(cmd->sk);
kfree(cmd->param);
kfree(cmd);
}
void mgmt_pending_remove(struct mgmt_pending_cmd *cmd)
{
mutex_lock(&cmd->hdev->mgmt_pending_lock);
list_del(&cmd->list);
mutex_unlock(&cmd->hdev->mgmt_pending_lock);
mgmt_pending_free(cmd);
}
void mgmt_mesh_foreach(struct hci_dev *hdev,
void (*cb)(struct mgmt_mesh_tx *mesh_tx, void *data),
void *data, struct sock *sk)
{
struct mgmt_mesh_tx *mesh_tx, *tmp;
list_for_each_entry_safe(mesh_tx, tmp, &hdev->mesh_pending, list) {
if (!sk || mesh_tx->sk == sk)
cb(mesh_tx, data);
}
}
struct mgmt_mesh_tx *mgmt_mesh_next(struct hci_dev *hdev, struct sock *sk)
{
struct mgmt_mesh_tx *mesh_tx;
if (list_empty(&hdev->mesh_pending))
return NULL;
list_for_each_entry(mesh_tx, &hdev->mesh_pending, list) {
if (!sk || mesh_tx->sk == sk)
return mesh_tx;
}
return NULL;
}
struct mgmt_mesh_tx *mgmt_mesh_find(struct hci_dev *hdev, u8 handle)
{
struct mgmt_mesh_tx *mesh_tx;
if (list_empty(&hdev->mesh_pending))
return NULL;
list_for_each_entry(mesh_tx, &hdev->mesh_pending, list) {
if (mesh_tx->handle == handle)
return mesh_tx;
}
return NULL;
}
struct mgmt_mesh_tx *mgmt_mesh_add(struct sock *sk, struct hci_dev *hdev,
void *data, u16 len)
{
struct mgmt_mesh_tx *mesh_tx;
mesh_tx = kzalloc(sizeof(*mesh_tx), GFP_KERNEL);
if (!mesh_tx)
return NULL;
hdev->mesh_send_ref++;
if (!hdev->mesh_send_ref)
hdev->mesh_send_ref++;
mesh_tx->handle = hdev->mesh_send_ref;
mesh_tx->index = hdev->id;
memcpy(mesh_tx->param, data, len);
mesh_tx->param_len = len;
mesh_tx->sk = sk;
sock_hold(sk);
list_add_tail(&mesh_tx->list, &hdev->mesh_pending);
return mesh_tx;
}
void mgmt_mesh_remove(struct mgmt_mesh_tx *mesh_tx)
{
list_del(&mesh_tx->list);
sock_put(mesh_tx->sk);
kfree(mesh_tx);
}