Re: [RFC c/r 4/4] c/r: prctl: Extend PR_SET_MM to set up more mm_structentries

[KOSAKI Motohiro]

>> +
>> +       case PR_SET_MM_AUXV:
>> +               if (arg4 > sizeof(mm->saved_auxv))
>> +                       goto out;
>> +               up_read(&mm->mmap_sem);
>> +
>> +               error = -EFAULT;
>> +               if (!copy_from_user(mm->saved_auxv, (const void __user *)addr, arg4))
>> +                       error = 0;
>> +
>> +               return error;
> 
> Is the mmap_sem released here because of the copy_from_user()? Is it
> still safe to write to saved_auxv?

Sure. It's unsafe.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/