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Date: Thu, 15 Feb 2024 09:03:02 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Zhu Yanjun" <yanjun.zhu@linux.dev>, "Arnd Bergmann" <arnd@kernel.org>,
 "Saeed Mahameed" <saeedm@nvidia.com>, "Leon Romanovsky" <leon@kernel.org>
Cc: "David S . Miller" <davem@davemloft.net>,
 "Eric Dumazet" <edumazet@google.com>, "Jakub Kicinski" <kuba@kernel.org>,
 "Paolo Abeni" <pabeni@redhat.com>, "Yevgeny Kliteynik" <kliteyn@nvidia.com>,
 "Alex Vesker" <valex@nvidia.com>, "Hamdan Igbaria" <hamdani@nvidia.com>,
 Netdev <netdev@vger.kernel.org>, linux-rdma@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] net/mlx5: fix possible stack overflows
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On Thu, Feb 15, 2024, at 01:18, Zhu Yanjun wrote:
> =E5=9C=A8 2024/2/13 18:08, Arnd Bergmann =E5=86=99=E9=81=93:

>>   static int
>> -dr_dump_rule_rx_tx(struct seq_file *file, struct mlx5dr_rule_rx_tx *=
rule_rx_tx,
>> +dr_dump_rule_rx_tx(struct seq_file *file, char *buff,
>> +		   struct mlx5dr_rule_rx_tx *rule_rx_tx,
>>   		   bool is_rx, const u64 rule_id, u8 format_ver)
>>   {
>>   	struct mlx5dr_ste *ste_arr[DR_RULE_MAX_STES + DR_ACTION_MAX_STES];
>> @@ -533,7 +532,7 @@ dr_dump_rule_rx_tx(struct seq_file *file, struct =
mlx5dr_rule_rx_tx *rule_rx_tx,
>>   		return 0;
>>  =20
>>   	while (i--) {
>> -		ret =3D dr_dump_rule_mem(file, ste_arr[i], is_rx, rule_id,
>
> Before buff is reused, I am not sure whether buff should be firstly=20
> zeroed or not.

I don't see why it would, but if you want to zero it, that would be
a separate patch that is already needed on the existing code,
which never zeroes its buffers.

    Arnd