Subject: Re: [PATCH v2] core: dev: don't call BUG() on bad input

From: Patrick McHardy <[email-masked]>
Date: Mon, 14 Feb 2011 16:41:03 +0100

Am 14.02.2011 16:16, schrieb Alexey Dobriyan:
> On Mon, Feb 14, 2011 at 4:42 PM, Vasiliy Kulikov <[email-masked]> wrote:
>> alloc_netdev() may be called with too long name (more that IFNAMSIZ bytes).
>> Currently this leads to BUG().  Other insane inputs (bad txqs, rxqs) and
>> even OOM don't lead to BUG().  Made alloc_netdev() return NULL, like on
>> other errors.
> 
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -5761,7 +5761,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
>>        size_t alloc_size;
>>        struct net_device *p;
>>
>> -       BUG_ON(strlen(name) >= sizeof(dev->name));
>> +       if (strnlen(name, sizeof(dev->name)) >= sizeof(dev->name)) {
>> +               pr_err("alloc_netdev: Too long device name\n");
>> +               return NULL;
>> +       }
> 
> Netdevice name isn't some random junk you get from userspace, so BUG is fine.

I agree, misuse of kernel APIs is not something we need to catch
verbosely.