Re: [PATCH 5/6] proc: make check_mem_permission() return an mm_struct on success

From: KOSAKI Motohiro
Date: Wed Mar 09 2011 - 01:20:25 EST


> This change allows us to take advantage of access_remote_vm(), which in turn
> enables a secure mem_write() implementation.
>
> The previous implementation of mem_write() was insecure since the target task
> could exec a setuid-root binary between the permission check and the actual
> write. Holding a reference to the target mm_struct eliminates this
> vulnerability.
>
> Signed-off-by: Stephen Wilson <wilsons@xxxxxxxx>

OK, I like this idea. So, I suppose you will resend newer version as applied Al's
comment and I'll be able to ack this.

Thanks.



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