[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <202306281053.EC5115465B@keescook>
Date: Wed, 28 Jun 2023 10:55:58 -0700
From: Kees Cook <keescook@...omium.org>
To: Yuxiao Zhang <yuxiaozhang@...gle.com>
Cc: Tony Luck <tony.luck@...el.com>,
"'Guilherme G . Piccoli'" <gpiccoli@...lia.com>,
Greg KH <gregkh@...uxfoundation.org>,
linux-hardening@...r.kernel.org, linux-kernel@...r.kernel.org,
wak@...gle.com
Subject: Re: [PATCH] pstore: ramoops: support pmsg size larger than kmalloc
limitation
On Tue, Jun 27, 2023 at 01:25:41PM -0700, Yuxiao Zhang wrote:
> Current pmsg implementation is using kmalloc for pmsg record buffer,
> which has max size limits based on page size. Currently even we
> allocate enough space with pmsg-size, pmsg will still fail if the
> file size is larger than what kmalloc allowed.
>
> Since we don't need physical contiguous memory for pmsg buffer
> , we can use kvmalloc to avoid such limitation.
Conceptually, I am fine with this change. I need a little time to trace
down the allocations. At first glance, I thought this patch only needed
to cover pstore_write_user_compat(), but I guess the read side needs to
be adjusted as well?
I'll double-check.
And yes, Greg's questions are all good -- fixing syntax and adding size
details in the commit log would be appreciated.
-Kees
--
Kees Cook
Powered by blists - more mailing lists