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

[ Upstream commit 333b4fd11e89b29c84c269123f871883a30be586 ]

[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: 7b064edae38d ("Bluetooth: Fix authentication if acl data comes before remote feature evt") Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org [Xiangyu: Modified to bp this commit to fix CVE-2024-49950] Signed-off-by: Xiangyu Chen xiangyu.chen@windriver.com --- net/bluetooth/hci_core.c | 2 ++ net/bluetooth/hci_event.c | 2 +- net/bluetooth/l2cap_core.c | 9 --------- 3 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 993b98257bc2..3039dc5fbe75 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3859,6 +3859,8 @@ 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) { diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 0c0141c59fd1..e5ca2d188c1a 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3789,7 +3789,7 @@ 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); diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 209c6d458d33..187c91843876 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4300,18 +4300,9 @@ static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn, 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) && - !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags)) - mgmt_device_connected(hdev, hcon, NULL, 0); - hci_dev_unlock(hdev); - l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0); return 0; }