From: Shuah Khan <skhan@linuxfoundation.org>
To: Felix Fietkau <nbd@nbd.name>,
lorenzo.bianconi83@gmail.com, ryder.lee@mediatek.com,
kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org,
matthias.bgg@gmail.com
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH] mt76: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()
Date: Fri, 12 Feb 2021 10:20:27 -0700 [thread overview]
Message-ID: <61994394-0d95-39eb-2a11-487ca7c6c37b@linuxfoundation.org> (raw)
In-Reply-To: <3949e1fc-c050-73e0-d02f-63a25c4821ef@nbd.name>
On 2/11/21 10:36 PM, Felix Fietkau wrote:
>
> On 2021-02-12 03:13, Shuah Khan wrote:
>> ieee80211_find_sta_by_ifaddr() must be called under the RCU lock and
>> the resulting pointer is only valid under RCU lock as well.
>>
>> Fix mt76_check_sta() to hold RCU read lock before it calls
>> ieee80211_find_sta_by_ifaddr() and release it when the resulting
>> pointer is no longer needed.
>>
>> This problem was found while reviewing code to debug RCU warn from
>> ath10k_wmi_tlv_parse_peer_stats_info() and a subsequent manual audit
>> of other callers of ieee80211_find_sta_by_ifaddr() that don't hold
>> RCU read lock.
>>
>> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> If I'm not mistaken, this patch is unnecessary. mt76_check_sta is only
> called from mt76_rx_poll_complete, which itself is only called under RCU
> lock.
>
Yes. You are right. I checked the caller of this routine and didn't
go further up. :)
thanks,
-- Shuah
next prev parent reply other threads:[~2021-02-12 17:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1613090339.git.skhan@linuxfoundation.org>
2021-02-12 2:13 ` [PATCH 1/2] ath9k: " Shuah Khan
2021-02-12 2:13 ` [PATCH] mt76: " Shuah Khan
2021-02-12 5:36 ` Felix Fietkau
2021-02-12 17:20 ` Shuah Khan [this message]
2021-02-12 2:13 ` [PATCH] rtw88: " Shuah Khan
2021-02-12 6:34 ` Felix Fietkau
2021-02-12 6:31 ` [PATCH 1/2] ath9k: " Felix Fietkau
2021-02-12 2:13 ` [PATCH 2/2] ath9k: fix ath_tx_process_buffer() potential null ptr dereference Shuah Khan
2021-02-16 7:03 ` Kalle Valo
2021-02-16 7:53 ` Felix Fietkau
2021-02-16 15:22 ` Shuah Khan
2021-02-17 7:30 ` Kalle Valo
2021-02-17 14:56 ` Shuah Khan
2021-02-17 20:28 ` Shuah Khan
2021-02-17 21:36 ` Felix Fietkau
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