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Date: Fri, 7 May 2010 17:47:45 +0800
Message-ID: <v2gbd0d95d71005070247j1f615a65mcbd52b5b6474206e@mail.gmail.com>
Subject: Re: [PATCH] Check kmalloc return value before use the buffer
From: Steven Liu <lingjiujianke@gmail.com>
To: nigel@tuxonice.net
Cc: Linus WALLEIJ <linus.walleij@stericsson.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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Hi, guy,

the code in arch/arm/mach-u300/dummyspichip.c is

    bigtxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);
    if (bigtxbuf_virtual == NULL) {
        status = -ENOMEM;
        goto out;
    }
    bigrxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);


if kmalloc memory space for bigrxbuf_virtual is NULL, when it have
kmalloc DMA_TEST_SIZE memory space for bigtxbuf_virtual,so ,if kmalloc
memory for bigtxbuf_virtual success and kmalloc memory for
bigrxbuf_virtual faild,i think we must kfree  bigtxbuf_virtual memory



best regards,



LiuQi
2010/5/7 Nigel Cunningham <nigel@tuxonice.net>:
> Hi.
>
> No commit comment?
>
> On 07/05/10 17:17, Steven Liu wrote:
>>
>> Signed-off-by: LiuQi<lingjiujianke@gmail.com>
>> ---
>>  arch/arm/mach-u300/dummyspichip.c |    5 +++++
>>  1 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/mach-u300/dummyspichip.c
>> b/arch/arm/mach-u300/dummyspichip.c
>> index 5f55012..df19f9b 100644
>> --- a/arch/arm/mach-u300/dummyspichip.c
>> +++ b/arch/arm/mach-u300/dummyspichip.c
>> @@ -64,6 +64,11 @@ static ssize_t dummy_looptest(struct device *dev,
>>                goto out;
>>        }
>>        bigrxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);
>> +       if (bigrxbuf_virtual == NULL) {
>> +               status = -ENOMEM;
>> +               kfree(bigtxbuf_virtual);
>
> Why kfree something you know is NULL?
>
> Regards,
>
> Nigel
>