Re: BUG: KASAN: null-ptr-deref in _raw_spin_lock_bh+0x4c/0xc0

[Eric Dumazet]

On Thu, Jan 19, 2023 at 2:41 AM Sungwoo Kim <iam@xxxxxxxxxxxx> wrote:
>
> Write of size 4 at addr 0000000000000098 by task kworker/u3:0/76
>
> CPU: 0 PID: 76 Comm: kworker/u3:0 Not tainted 6.1.0-rc2 #129
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
> Workqueue: hci0 hci_rx_work
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x7b/0xb3
>  print_report+0xed/0x200
>  ? __virt_addr_valid+0x5c/0x240
>  ? kasan_addr_to_slab+0xd/0xa0
>  ? _raw_spin_lock_bh+0x4c/0xc0
>  kasan_report+0xd3/0x100
>  ? _raw_spin_lock_bh+0x4c/0xc0
>  kasan_check_range+0x2d3/0x310
>  __kasan_check_write+0x14/0x20
>  _raw_spin_lock_bh+0x4c/0xc0
>  lock_sock_nested+0x3f/0x160
>  ? queue_work_on+0x90/0xd0
>  l2cap_sock_set_shutdown_cb+0x3d/0x60
>  l2cap_disconnect_req+0x1e3/0x2e0
>  l2cap_bredr_sig_cmd+0x3d2/0x5ec0
>  ? vprintk_emit+0x29b/0x4d0
>  ? vprintk_default+0x2b/0x30
>  ? vprintk+0xdc/0x100
>  ? _printk+0x67/0x85
>  ? bt_err+0x7f/0xc0
>  ? bt_err+0x9a/0xc0
>  l2cap_recv_frame+0x7bc/0x4e10
>  ? _printk+0x67/0x85
>  ? bt_err+0x7f/0xc0
>  ? __wake_up_klogd+0xc4/0xf0
>  l2cap_recv_acldata+0x327/0x650
>  ? hci_conn_enter_active_mode+0x1b7/0x1f0
>  hci_rx_work+0x6b7/0x7c0
>  process_one_work+0x461/0xaf0
>  worker_thread+0x5f8/0xba0
>  kthread+0x1c5/0x200
>  ? process_one_work+0xaf0/0xaf0
>  ? kthread_blkcg+0x90/0x90
>  ret_from_fork+0x1f/0x30
>  </TASK>

If you plan sending more stack traces like that in the future, always
run scripts/decode_stacktrace.sh
so that the public report includes symbols.

Thanks.