Re: [PATCH] module: prevent warning when finit_module a 0 sized file

From: Sasha Levin
Date: Thu Jan 03 2013 - 17:15:14 EST

On 01/02/2013 07:41 PM, Rusty Russell wrote:
> Sasha Levin <sasha.levin@xxxxxxxxxx> writes:
>> If we try to finit_module on a file sized 0 bytes vmalloc will
>> scream and spit out a warning.
>> Since modules have to be bigger than 0 bytes anyways we can just
>> check that beforehand and avoid the warning.
> Applied, but I added the comment you somehow missed :)


I do have a somewhat related follow-up question:

When init_module() goes through the module loading process, it will try to vmalloc()
whatever size passed to it by the user, which may cause vmalloc() to scream and shout
if the size passed from userspace is too big.

Do you think that reading just the header and doing a quick elf_header_check() on
it before trying to read the entire file would make sense here?

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