Re: [PATCH v3] kernel: kallsyms: memory override issue, need check destination buffer length

From: Rusty Russell
Date: Mon Apr 15 2013 - 19:17:41 EST


Chen Gang <gang.chen@xxxxxxxxxxx> writes:

> We don't export any symbols > 128 characters, but if we did then
> kallsyms_expand_symbol() would overflow the buffer handed to it.
> So we need check destination buffer length when copying.
>
> the related test:
> if we define an EXPORT function which name more than 128.
> will panic when call kallsyms_lookup_name by init_kprobes on booting.
> after check the length (provide this patch), it is ok.
>
> Implementaion:
> add additional destination buffer length parameter (maxlen)
> if uncompressed string is too long (>= maxlen), it will be truncated.
> not check the parameters whether valid, since it is a static function.

Thanks, applied.

I've put this in my modules-next branch.

Cheers,
Rusty.
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