From: Kees Cook <keescook@chromium.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Bill Metzenthen <billm@melbpc.org.au>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
the arch/x86 maintainers <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] x86: math-emu: check __copy_from_user result
Date: Wed, 2 Oct 2019 23:26:02 -0700 [thread overview]
Message-ID: <201910022325.D6769F3@keescook> (raw)
In-Reply-To: <CAK8P3a2BKyz8Myrd-ob9t5FyJmQ_FVUmNMYbfzr6YUZWfyH4XQ@mail.gmail.com>
On Wed, Oct 02, 2019 at 09:11:23AM +0200, Arnd Bergmann wrote:
> On Wed, Oct 2, 2019 at 1:39 AM Kees Cook <keescook@chromium.org> wrote:
>
> > > diff --git a/arch/x86/math-emu/reg_ld_str.c b/arch/x86/math-emu/reg_ld_str.c
> > > index f3779743d15e..fe6246ff9887 100644
> > > --- a/arch/x86/math-emu/reg_ld_str.c
> > > +++ b/arch/x86/math-emu/reg_ld_str.c
> > > @@ -85,7 +85,7 @@ int FPU_load_extended(long double __user *s, int stnr)
> > >
> > > RE_ENTRANT_CHECK_OFF;
> > > FPU_access_ok(s, 10);
> > > - __copy_from_user(sti_ptr, s, 10);
> > > + FPU_copy_from_user(sti_ptr, s, 10);
> >
> > These access_ok() checks seem redundant everywhere in this file (after
> > your switch from __copy* to copy*. I mean, I guess, just leave them, but
> > *shrug*
>
> There have always been duplicate/inconsistent for the get_user/put_user
> case. I considered cleaning it all up but then decided to touch it as little
> as possible.
Yeah, at this point, I'd agree. :)
--
Kees Cook
next prev parent reply other threads:[~2019-10-03 6:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-01 14:23 [PATCH 1/2] x86: math-emu: check __copy_from_user result Arnd Bergmann
2019-10-01 14:23 ` [PATCH 2/2] x86: math-emu: limit MATH_EMULATION to 486SX compatibles Arnd Bergmann
2019-10-01 21:54 ` Kees Cook
2019-10-03 9:33 ` [tip: x86/cpu] x86/math-emu: Limit " tip-bot2 for Arnd Bergmann
2019-10-01 23:39 ` [PATCH 1/2] x86: math-emu: check __copy_from_user result Kees Cook
2019-10-02 7:11 ` Arnd Bergmann
2019-10-03 6:26 ` Kees Cook [this message]
2019-10-03 9:33 ` [tip: x86/cpu] x86/math-emu: Check __copy_from_user() result tip-bot2 for Arnd Bergmann
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