Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   liqiong <liqiong@nfschina.com>
Subject: Re: [PATCH] smackfs: check for allocation failure of kmalloc()
To:     Casey Schaufler <casey@schaufler-ca.com>,
        James Morris <jmorris@namei.org>,
        "Serge E . Hallyn" <serge@hallyn.com>
Cc:     linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, yuzhe@nfschina.com,
        renyu@nfschina.com
References: <20220613062202.29194-1-liqiong@nfschina.com>
 <88718d10-4435-f5a8-9123-afc73257e0ca@schaufler-ca.com>
Message-ID: <f2e6beb0-bce9-0e73-aefc-8f6c6b5509f4@nfschina.com>
Date:   Mon, 13 Jun 2022 23:33:16 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.2.1
MIME-Version: 1.0
In-Reply-To: <88718d10-4435-f5a8-9123-afc73257e0ca@schaufler-ca.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Precedence: bulk


在 2022年06月13日 22:53, Casey Schaufler 写道:
> On 6/12/2022 11:22 PM, Li Qiong wrote:
>> As the possible failure of the kmalloc(), it should be better
>> to check it and print a warning message.
>
> The allocation is done with __GFP_NOFAIL, which assures
> it will not fail.

Thanks,  my mistake.
Drop this patch.


>
>>
>> Signed-off-by: Li Qiong <liqiong@nfschina.com>
>> ---
>>   security/smack/smackfs.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
>> index 4b58526450d4..0d11ba3cb4cd 100644
>> --- a/security/smack/smackfs.c
>> +++ b/security/smack/smackfs.c
>> @@ -695,6 +695,11 @@ static void smk_cipso_doi(void)
>>                  __func__, __LINE__, rc);
>>         doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL | __GFP_NOFAIL);
>> +    if (unlikely(!doip)) {
>> +        printk(KERN_WARNING "%s:%d failed to allocate a memory for doip\n",
>> +               __func__, __LINE__);
>> +        return;
>> +    }
>>       doip->map.std = NULL;
>>       doip->doi = smk_cipso_doi_value;
>>       doip->type = CIPSO_V4_MAP_PASS;