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Subject: Re: [PATCH] rtlwifi: Fix null-pointer dereferences in error handling
 code of rtl_pci_probe()
From:   Kalle Valo <kvalo@codeaurora.org>
In-Reply-To: <20190514123439.10524-1-baijiaju1990@gmail.com>
References: <20190514123439.10524-1-baijiaju1990@gmail.com>
To:     Jia-Ju Bai <baijiaju1990@gmail.com>
Cc:     pkshih@realtek.com, davem@davemloft.net,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
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Message-Id: <20190528115555.301E760F3C@smtp.codeaurora.org>
Date:   Tue, 28 May 2019 11:55:50 +0000 (UTC)
Sender: linux-wireless-owner@vger.kernel.org
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Jia-Ju Bai <baijiaju1990@gmail.com> 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@gmail.com>

Ping & Larry, is this ok to take?

-- 
https://patchwork.kernel.org/patch/10942971/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches