From: Christoph Hellwig <hch@infradead.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@kernel.org>,
linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Christoph Hellwig <hch@infradead.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-kernel@vger.kernel.org, Linux-MM <linux-mm@kvack.org>,
kexec@lists.infradead.org
Subject: Re: [PATCH v3 1/4] kexec: simplify compat_sys_kexec_load
Date: Tue, 18 May 2021 07:40:29 +0100 [thread overview]
Message-ID: <YKNhXQ883lRbqQGA@infradead.org> (raw)
In-Reply-To: <m1y2cc3d97.fsf@fess.ebiederm.org>
On Mon, May 17, 2021 at 10:57:24PM -0500, Eric W. Biederman wrote:
> We open ourselves up to bugs whenever we lie to the type system.
>
> Skimming through the code it looks like it should be possible
> to not need the in_compat_syscall and the casts to the wrong
> type by changing the order of the code a little bit.
What kind of bug do you expect? We must only copy from user addresses
once anyway. I've never seen bugs due the use of in_compat_syscall,
but plenty due to cruft code trying to avoid it.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@kernel.org>,
linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Christoph Hellwig <hch@infradead.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-kernel@vger.kernel.org, Linux-MM <linux-mm@kvack.org>,
kexec@lists.infradead.org
Subject: Re: [PATCH v3 1/4] kexec: simplify compat_sys_kexec_load
Date: Tue, 18 May 2021 07:40:29 +0100 [thread overview]
Message-ID: <YKNhXQ883lRbqQGA@infradead.org> (raw)
In-Reply-To: <m1y2cc3d97.fsf@fess.ebiederm.org>
On Mon, May 17, 2021 at 10:57:24PM -0500, Eric W. Biederman wrote:
> We open ourselves up to bugs whenever we lie to the type system.
>
> Skimming through the code it looks like it should be possible
> to not need the in_compat_syscall and the casts to the wrong
> type by changing the order of the code a little bit.
What kind of bug do you expect? We must only copy from user addresses
once anyway. I've never seen bugs due the use of in_compat_syscall,
but plenty due to cruft code trying to avoid it.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@infradead.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@kernel.org>,
linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Christoph Hellwig <hch@infradead.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
linux-kernel@vger.kernel.org, Linux-MM <linux-mm@kvack.org>,
kexec@lists.infradead.org
Subject: Re: [PATCH v3 1/4] kexec: simplify compat_sys_kexec_load
Date: Tue, 18 May 2021 07:40:29 +0100 [thread overview]
Message-ID: <YKNhXQ883lRbqQGA@infradead.org> (raw)
In-Reply-To: <m1y2cc3d97.fsf@fess.ebiederm.org>
On Mon, May 17, 2021 at 10:57:24PM -0500, Eric W. Biederman wrote:
> We open ourselves up to bugs whenever we lie to the type system.
>
> Skimming through the code it looks like it should be possible
> to not need the in_compat_syscall and the casts to the wrong
> type by changing the order of the code a little bit.
What kind of bug do you expect? We must only copy from user addresses
once anyway. I've never seen bugs due the use of in_compat_syscall,
but plenty due to cruft code trying to avoid it.
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-05-18 6:41 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 20:33 [PATCH v3 0/4] compat: remove compat_alloc_user_space callers Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` [PATCH v3 1/4] kexec: simplify compat_sys_kexec_load Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-18 3:57 ` Eric W. Biederman
2021-05-18 3:57 ` Eric W. Biederman
2021-05-18 3:57 ` Eric W. Biederman
2021-05-18 3:57 ` Eric W. Biederman
2021-05-18 6:40 ` Christoph Hellwig [this message]
2021-05-18 6:40 ` Christoph Hellwig
2021-05-18 6:40 ` Christoph Hellwig
2021-05-18 7:44 ` Arnd Bergmann
2021-05-18 7:44 ` Arnd Bergmann
2021-05-18 7:44 ` Arnd Bergmann
2021-05-18 7:44 ` Arnd Bergmann
2021-05-18 6:38 ` Christoph Hellwig
2021-05-18 6:38 ` Christoph Hellwig
2021-05-18 6:38 ` Christoph Hellwig
2021-05-18 7:47 ` Arnd Bergmann
2021-05-18 7:47 ` Arnd Bergmann
2021-05-18 7:47 ` Arnd Bergmann
2021-05-18 7:47 ` Arnd Bergmann
2021-05-18 13:41 ` Eric W. Biederman
2021-05-18 13:41 ` Eric W. Biederman
2021-05-18 13:41 ` Eric W. Biederman
2021-05-18 13:41 ` Eric W. Biederman
2021-05-18 14:05 ` Arnd Bergmann
2021-05-18 14:05 ` Arnd Bergmann
2021-05-18 14:05 ` Arnd Bergmann
2021-05-18 14:05 ` Arnd Bergmann
2021-05-18 14:17 ` Arnd Bergmann
2021-05-18 14:17 ` Arnd Bergmann
2021-05-18 14:17 ` Arnd Bergmann
2021-05-18 14:17 ` Arnd Bergmann
2021-05-18 16:01 ` Eric W. Biederman
2021-05-18 16:01 ` Eric W. Biederman
2021-05-18 16:01 ` Eric W. Biederman
2021-05-18 16:01 ` Eric W. Biederman
2021-05-18 22:45 ` Eric W. Biederman
2021-05-18 22:45 ` Eric W. Biederman
2021-05-18 22:45 ` Eric W. Biederman
2021-05-18 22:45 ` Eric W. Biederman
2021-05-19 9:55 ` Arnd Bergmann
2021-05-19 9:55 ` Arnd Bergmann
2021-05-19 9:55 ` Arnd Bergmann
2021-05-19 9:55 ` Arnd Bergmann
2021-05-18 20:47 ` David Laight
2021-05-18 20:47 ` David Laight
2021-05-18 20:47 ` David Laight
2021-05-17 20:33 ` [PATCH v3 2/4] mm: simplify compat_sys_move_pages Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-18 6:42 ` Christoph Hellwig
2021-05-18 6:42 ` Christoph Hellwig
2021-05-18 6:42 ` Christoph Hellwig
2021-05-18 20:49 ` David Laight
2021-05-18 20:49 ` David Laight
2021-05-18 20:49 ` David Laight
2021-05-19 13:41 ` Arnd Bergmann
2021-05-19 13:41 ` Arnd Bergmann
2021-05-19 13:41 ` Arnd Bergmann
2021-05-19 13:41 ` Arnd Bergmann
2021-05-17 20:33 ` [PATCH v3 3/4] mm: simplify compat numa syscalls Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-18 6:52 ` Christoph Hellwig
2021-05-18 6:52 ` Christoph Hellwig
2021-05-18 6:52 ` Christoph Hellwig
2021-05-17 20:33 ` [PATCH v3 4/4] compat: remove some compat entry points Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-17 20:33 ` Arnd Bergmann
2021-05-18 6:55 ` Christoph Hellwig
2021-05-18 6:55 ` Christoph Hellwig
2021-05-18 6:55 ` Christoph Hellwig
2021-05-19 20:33 ` Thomas Gleixner
2021-05-19 20:33 ` Thomas Gleixner
2021-05-19 20:33 ` Thomas Gleixner
2021-05-19 21:00 ` Arnd Bergmann
2021-05-19 21:00 ` Arnd Bergmann
2021-05-19 21:00 ` Arnd Bergmann
2021-05-19 21:00 ` Arnd Bergmann
2021-05-20 9:21 ` Arnd Bergmann
2021-05-20 9:21 ` Arnd Bergmann
2021-05-20 9:21 ` Arnd Bergmann
2021-05-20 9:21 ` Arnd Bergmann
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