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From: Andy Lutomirski <luto@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>,
	linux-arch <linux-arch@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	"open list:MIPS" <linux-mips@vger.kernel.org>,
	X86 ML <x86@kernel.org>, Will Deacon <will.deacon@arm.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Russell King <linux@armlinux.org.uk>,
	Paul Burton <paul.burton@mips.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>, Stephen Boyd <sboyd@kernel.org>,
	Mark Salyzyn <salyzyn@android.com>,
	Kees Cook <keescook@chromium.org>,
	Peter Collingbourne <pcc@google.com>,
	Dmitry Safonov <0x7f454c46@gmail.com>,
	Andrei Vagin <avagin@openvz.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Marc Zyngier <maz@kernel.org>,
	Mark Rutland <Mark.Rutland@arm.com>,
	Will Deacon <will@kernel.org>
Subject: Re: [PATCH v4 18/26] arm64: vdso32: Replace TASK_SIZE_32 check in vgettimeofday
Date: Thu, 19 Mar 2020 08:49:44 -0700	[thread overview]
Message-ID: <CALCETrVWPNaJMbYoXbnWsALXKrhHMaePOUvY0DmXpvte8Zz9Zw@mail.gmail.com> (raw)
In-Reply-To: <20200317143834.GC632169@arrakis.emea.arm.com>

On Tue, Mar 17, 2020 at 7:38 AM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Tue, Mar 17, 2020 at 12:22:12PM +0000, Vincenzo Frascino wrote:
> > diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c
> > index 54fc1c2ce93f..91138077b073 100644
> > --- a/arch/arm64/kernel/vdso32/vgettimeofday.c
> > +++ b/arch/arm64/kernel/vdso32/vgettimeofday.c
> > @@ -8,11 +8,14 @@
> >  #include <linux/time.h>
> >  #include <linux/types.h>
> >
> > +#define VALID_CLOCK_ID(x) \
> > +     ((x >= 0) && (x < VDSO_BASES))
> > +
> >  int __vdso_clock_gettime(clockid_t clock,
> >                        struct old_timespec32 *ts)
> >  {
> >       /* The checks below are required for ABI consistency with arm */
> > -     if ((u32)ts >= TASK_SIZE_32)
> > +     if ((u32)ts > UINTPTR_MAX - sizeof(*ts) + 1)
> >               return -EFAULT;
> >
> >       return __cvdso_clock_gettime32(clock, ts);
>
> I probably miss something but I can't find the TASK_SIZE check in the
> arch/arm/vdso/vgettimeofday.c code. Is this done elsewhere?
>

Can you not just remove the TASK_SIZE_32 check entirely?  If you pass
a garbage address to the vDSO, you are quite likely to get SIGSEGV.
Why does this particular type of error need special handling?

  parent reply	other threads:[~2020-03-19 15:50 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-17 12:21 [PATCH v4 00/26] Introduce common headers for vDSO Vincenzo Frascino
2020-03-17 12:21 ` [PATCH v4 01/26] linux/const.h: Extract common header " Vincenzo Frascino
2020-03-17 12:21 ` [PATCH v4 02/26] linux/bits.h: " Vincenzo Frascino
2020-03-17 12:21 ` [PATCH v4 03/26] linux/limits.h: " Vincenzo Frascino
2020-03-17 12:21 ` [PATCH v4 04/26] x86:Introduce asm/vdso/clocksource.h Vincenzo Frascino
2020-03-17 12:21 ` [PATCH v4 05/26] arm: Introduce asm/vdso/clocksource.h Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 06/26] arm64: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 07/26] mips: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 08/26] linux/clocksource.h: Extract common header for vDSO Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 09/26] linux/math64.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 10/26] linux/time.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 11/26] linux/time32.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 12/26] linux/time64.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 13/26] linux/jiffies.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 14/26] linux/ktime.h: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 15/26] common: Introduce processor.h Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 16/26] scripts: Fix the inclusion order in modpost Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 17/26] linux/elfnote.h: Replace elf.h with UAPI equivalent Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 18/26] arm64: vdso32: Replace TASK_SIZE_32 check in vgettimeofday Vincenzo Frascino
2020-03-17 14:38   ` Catalin Marinas
2020-03-17 15:04     ` Vincenzo Frascino
2020-03-17 15:50       ` Catalin Marinas
2020-03-17 16:40         ` Vincenzo Frascino
2020-03-17 16:43           ` Vincenzo Frascino
2020-03-17 17:48           ` Catalin Marinas
2020-03-18 16:14             ` Vincenzo Frascino
2020-03-18 18:36               ` Catalin Marinas
2020-03-19 12:38                 ` Vincenzo Frascino
2020-03-19 18:10                   ` Catalin Marinas
2020-03-20 13:05                     ` Vincenzo Frascino
2020-03-20 14:22                       ` Catalin Marinas
2020-03-20 14:41                         ` Vincenzo Frascino
2020-03-19 15:49     ` Andy Lutomirski [this message]
2020-03-19 16:58       ` Vincenzo Frascino
2020-03-19 18:32         ` Will Deacon
2020-03-21 14:33   ` [tip: timers/core] arm64: vdso32: Code clean up tip-bot2 for Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 19/26] arm64: Introduce asm/vdso/processor.h Vincenzo Frascino
2020-03-17 17:52   ` Catalin Marinas
2020-03-17 12:22 ` [PATCH v4 20/26] arm64: vdso: Include common headers in the vdso library Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 21/26] arm64: vdso32: " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 22/26] mips: vdso: Enable mips to use common headers Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 23/26] x86: vdso: Enable x86 " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 24/26] arm: vdso: Enable arm " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 25/26] lib: vdso: Enable " Vincenzo Frascino
2020-03-17 12:22 ` [PATCH v4 26/26] arm64: vdso32: Enable Clang Compilation Vincenzo Frascino

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