[BUG] rtl8188eu: Some possible sleep-in-atomic bugs in ips_leave

[Jia-Ju Bai]

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On 2017/10/8 20:13, Jia-Ju Bai wrote:
> The driver may sleep under a spinlock when calling the function 
> "ips_leave", which causes some possible sleep-in-atomic bugs.
> Here are several examples:
> rtw_set_802_11_disassociate (acquire the spinlock)
>   _rtw_pwr_wakeup
>     ips_leave
>       mutex_lock --> may sleep
>
> rtw_set_802_11_disassociate (acquire the spinlock)
>   _rtw_pwr_wakeup
>     ips_leave
>       rtw_ips_pwr_up
>         ips_netdrv_open
>           rtw_hal_init
>             rtl8188eu_hal_init
>               rtl88eu_download_fw
>                 request_firmware --> may sleep
>                 kmalloc --> may sleep
>
> rtw_set_802_11_disassociate (acquire the spinlock)
>   _rtw_pwr_wakeup
>     ips_leave
>       rtw_set_key
>         kzalloc(GFP_KERNEL) --> may sleep
>
> All these bugs are caused by that "ips_leave" calls some sleep-able 
> functions.
> A possible fix is to release the spinlock before calling "ips_leave", 
> and acquire the spinlock again after it.
>
> These bugs are found by my static analysis tool and my code review.
>
>
> Thanks,
> Jia-Ju Bai