linux-kernel - Re: [PATCH net 2/3] net: hibmcge: fix the division by zero issue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3bf4236a-2f68-4c09-a9bc-9534111854f2@huawei.com>
Date: Fri, 1 Aug 2025 18:46:16 +0800
From: Jijie Shao <shaojijie@...wei.com>
To: Simon Horman <horms@...nel.org>
CC: <shaojijie@...wei.com>, <davem@...emloft.net>, <edumazet@...gle.com>,
	<kuba@...nel.org>, <pabeni@...hat.com>, <andrew+netdev@...n.ch>,
	<shenjian15@...wei.com>, <liuyonglong@...wei.com>, <chenhao418@...wei.com>,
	<jonathan.cameron@...wei.com>, <shameerali.kolothum.thodi@...wei.com>,
	<salil.mehta@...wei.com>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net 2/3] net: hibmcge: fix the division by zero issue


on 2025/8/1 18:11, Simon Horman wrote:
> On Thu, Jul 31, 2025 at 09:47:48PM +0800, Jijie Shao wrote:
>> When the network port is down, the queue is released, and ring->len is 0.
>> In debugfs, hbg_get_queue_used_num() will be called,
>> which may lead to a division by zero issue.
>>
>> This patch adds a check, if ring->len is 0,
>> hbg_get_queue_used_num() directly returns 0.
>>
>> Fixes: 40735e7543f9 ("net: hibmcge: Implement .ndo_start_xmit function")
>> Signed-off-by: Jijie Shao <shaojijie@...wei.com>
> Thanks,
>
> Thinking aloud:
>
> I see that hbg_get_queue_used_num() can be called for both RX and TX
> rings via the debugfs code hbg_dbg_ring(). And that hbg_net_stop()
> clears the RX and TX ring configuration using hbg_txrx_uninit().

Yes, yes.

> So I agree that when the port is down ring-len will be 0.
>
> Reviewed-by: Simon Horman <horms@...nel.org>
>
>