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From: Subhashini Rao Beerisetty <subhashbeerisetty@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: "Randy Dunlap" <rdunlap@infradead.org>,
	"Valdis Klētnieks" <valdis.kletnieks@vt.edu>,
	LKML <linux-kernel@vger.kernel.org>,
	kernelnewbies <kernelnewbies@kernelnewbies.org>
Subject: Re: general protection fault vs Oops
Date: Mon, 18 May 2020 11:15:34 +0530	[thread overview]
Message-ID: <CAPY=qRQez4JRLGcwBq_3_AGmtH36FRrKjhCWvkhrnQxvBJEnOw@mail.gmail.com> (raw)
In-Reply-To: <CAM_iQpXzeMjAUW0LNMpGf+bqykU8fjOJmy=CDdNEPQNpSB4raA@mail.gmail.com>

On Mon, May 18, 2020 at 2:16 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> On Sat, May 16, 2020 at 9:16 AM Subhashini Rao Beerisetty
> <subhashbeerisetty@gmail.com> wrote:
> > Yes, those are out-of-tree modules. Basically, my question is, in
> > general what is the difference between 'general protection fault' and
> > 'Oops' failure in kernel mode.
>
> For your case, they are likely just different consequences of a same
> memory error. Let's assume it is a use-after-free, the behavior is UAF
> is undefined: If that memory freed by kernel is also unmapped from
> kernel address space, you would get a page fault when using it
> afterward, that is an Oops. Or if that memory freed by kernel gets
> reallocated and remapped as read-only, you would get a general
> protection error when you writing to it afterward.
Cool, thanks for the clarification.

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      reply	other threads:[~2020-05-18  5:47 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-16 12:35 general protection fault vs Oops Subhashini Rao Beerisetty
2020-05-16 13:53 ` Valdis Klētnieks
2020-05-16 15:10   ` Subhashini Rao Beerisetty
2020-05-16 15:59   ` Randy Dunlap
2020-05-16 16:15     ` Subhashini Rao Beerisetty
2020-05-17 20:46       ` Cong Wang
2020-05-18  5:45         ` Subhashini Rao Beerisetty [this message]

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