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Bluetooth: L2CAP: Fix uaf in l2cap_connect

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[Syzbot reported]
BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949
Read of size 8 at addr ffff8880241e9800 by task kworker/u9:0/54

CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:0 Not tainted 6.11.0-rc6-syzkaller-00268-g788220eee30d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: hci2 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949
 l2cap_connect_req net/bluetooth/l2cap_core.c:4080 [inline]
 l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:4772 [inline]
 l2cap_sig_channel net/bluetooth/l2cap_core.c:5543 [inline]
 l2cap_recv_frame+0xf0b/0x8eb0 net/bluetooth/l2cap_core.c:6825
 l2cap_recv_acldata+0x9b4/0xb70 net/bluetooth/l2cap_core.c:7514
 hci_acldata_packet net/bluetooth/hci_core.c:3791 [inline]
 hci_rx_work+0xaab/0x1610 net/bluetooth/hci_core.c:4028
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
...

Freed by task 5245:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2256 [inline]
 slab_free mm/slub.c:4477 [inline]
 kfree+0x12a/0x3b0 mm/slub.c:4598
 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline]
 l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802
 l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7241
 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
 hci_conn_failed+0x1c3/0x370 net/bluetooth/hci_conn.c:1265
 hci_abort_conn_sync+0x75a/0xb50 net/bluetooth/hci_sync.c:5583
 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2917
 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:328
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Reported-by: syzbot+c12e2f941af1feb5632c@syzkaller.appspotmail.com
Tested-by: syzbot+c12e2f941af1feb5632c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c12e2f941af1feb5632c
Fixes: 7b064edae3 ("Bluetooth: Fix authentication if acl data comes before remote feature evt")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This commit is contained in:
Luiz Augusto von Dentz 2024-09-23 12:47:39 -04:00
parent f53e1c9c72
commit 333b4fd11e
3 changed files with 3 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/bluetooth/hci_core.c
View File

@ -3782,6 +3782,8 @@ static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
hci_dev_lock(hdev);
conn = hci_conn_hash_lookup_handle(hdev, handle);
if (conn && hci_dev_test_flag(hdev, HCI_MGMT))
mgmt_device_connected(hdev, conn, NULL, 0);
hci_dev_unlock(hdev);
if (conn) {

2
net/bluetooth/hci_event.c
View File

@ -3706,7 +3706,7 @@ static void hci_remote_features_evt(struct hci_dev *hdev, void *data,
goto unlock;
}
if (!ev->status && !test_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags)) {
if (!ev->status) {
struct hci_cp_remote_name_req cp;
memset(&cp, 0, sizeof(cp));
bacpy(&cp.bdaddr, &conn->dst);

8
net/bluetooth/l2cap_core.c
View File

@ -4066,17 +4066,9 @@ response:
static int l2cap_connect_req(struct l2cap_conn *conn,
struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
{
struct hci_dev *hdev = conn->hcon->hdev;
struct hci_conn *hcon = conn->hcon;
if (cmd_len < sizeof(struct l2cap_conn_req))
return -EPROTO;
hci_dev_lock(hdev);
if (hci_dev_test_flag(hdev, HCI_MGMT))
mgmt_device_connected(hdev, hcon, NULL, 0);
hci_dev_unlock(hdev);
l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP);
return 0;
}