Larry Finger <Larry.Finger@xxxxxxxxxxxx> writes: > On 5/28/19 6:55 AM, Kalle Valo wrote: >> Jia-Ju Bai <baijiaju1990@xxxxxxxxx> wrote: >> >>> *BUG 1: >>> In rtl_pci_probe(), when rtlpriv->cfg->ops->init_sw_vars() fails, >>> rtl_deinit_core() in the error handling code is executed. >>> rtl_deinit_core() calls rtl_free_entries_from_scan_list(), which uses >>> rtlpriv->scan_list.list in list_for_each_entry_safe(), but it has been >>> initialized. Thus a null-pointer dereference occurs. >>> The reason is that rtlpriv->scan_list.list is initialized by >>> INIT_LIST_HEAD() in rtl_init_core(), which has not been called. >>> >>> To fix this bug, rtl_deinit_core() should not be called when >>> rtlpriv->cfg->ops->init_sw_vars() fails. >>> >>> *BUG 2: >>> In rtl_pci_probe(), rtl_init_core() can fail when rtl_regd_init() in >>> this function fails, and rtlpriv->scan_list.list has not been >>> initialized by INIT_LIST_HEAD(). Then, rtl_deinit_core() in the error >>> handling code of rtl_pci_probe() is executed. Finally, a null-pointer >>> dereference occurs due to the same reason of the above bug. >>> >>> To fix this bug, the initialization of lists in rtl_init_core() are >>> performed before the call to rtl_regd_init(). >>> >>> These bugs are found by a runtime fuzzing tool named FIZZER written by >>> us. >>> >>> Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx> >> >> Ping & Larry, is this ok to take? >> > > Kalle, > > Not at the moment. In reviewing the code, I was unable to see how this > situation could develop, and his backtrace did not mention any rtlwifi > code. For that reason, I asked him to add printk stat4ements to show > the last part of rtl_pci that executed correctly. In > https://marc.info/?l=linux-wireless&m=155788322631134&w=2, he promised > to do that, but I have not seen the result. Ok, thanks. I'll then drop this, please resubmit once everything is understood and the patch is ready to be applied. -- Kalle Valo
