From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
LKML <linux-kernel@vger.kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
Rik van Riel <riel@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"David S. Miller" <davem@davemloft.net>,
"x86@kernel.org" <x86@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
Mathias Krause <minipli@googlemail.com>, Jan Kara <jack@suse.cz>,
Vitaly Wool <vitalywool@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Dmitry Vyukov <dvyukov@google.com>,
Laura Abbott <labbott@fedoraproject.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
linux-ia64@vger.kernel.org,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
sparclinux <sparclinux@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 12:45:51 -0500 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
LKML <linux-kernel@vger.kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
Rik van Riel <riel@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"David S. Miller" <davem@davemloft.net>,
"x86@kernel.org" <x86@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>
Subject: Re: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 12:45:51 -0500 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
LKML <linux-kernel@vger.kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
Rik van Riel <riel@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"David S. Miller" <davem@davemloft.net>,
"x86@kernel.org" <x86@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
Mathias Krause <minipli@googlemail.com>, Jan Kara <jack@suse.cz>,
Vitaly Wool <vitalywool@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Dmitry Vyukov <dvyukov@google.com>,
Laura Abbott <labbott@fedoraproject.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
linux-ia64@vger.kernel.org,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
sparclinux <sparclinux@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 17:45:51 +0000 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
LKML <linux-kernel@vger.kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
Rik van Riel <riel@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"David S. Miller" <davem@davemloft.net>,
"x86@kernel.org" <x86@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
Mathias Krause <minipli@googlemail.com>, Jan Kara <jack@suse.cz>,
Vitaly Wool <vitalywool@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Dmitry Vyukov <dvyukov@google.com>,
Laura Abbott <labbott@fedoraproject.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
linux-ia64@vger.kernel.org,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
sparclinux <sparclinux@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 12:45:51 -0500 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
--
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WARNING: multiple messages have this Message-ID (diff)
From: jpoimboe@redhat.com (Josh Poimboeuf)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 12:45:51 -0500 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
LKML <linux-kernel@vger.kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
Rik van Riel <riel@redhat.com>,
Casey Schaufler <casey@schaufler-ca.com>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Tony Luck <tony.luck@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"David S. Miller" <davem@davemloft.net>,
"x86@kernel.org" <x86@kernel.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
Mathias Krause <minipli@googlemail.com>, Jan Kara <jack@suse.cz>,
Vitaly Wool <vitalywool@gmail.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Dmitry Vyukov <dvyukov@google.com>,
Laura Abbott <labbott@fedoraproject.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
linux-ia64@vger.kernel.org,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
sparclinux <sparclinux@vger.kernel.org>,
linux-arch <linux-arch@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: [kernel-hardening] Re: [PATCH v3 02/11] mm: Hardened usercopy
Date: Fri, 22 Jul 2016 12:45:51 -0500 [thread overview]
Message-ID: <20160722174551.jddle6mf7zlq6xmb@treble> (raw)
In-Reply-To: <CAGXu5jLCu1Vv0uugKZrsjSEsoABgXJSOJ8GkKmrHbvj9jkC2YA@mail.gmail.com>
On Thu, Jul 21, 2016 at 11:34:25AM -0700, Kees Cook wrote:
> On Wed, Jul 20, 2016 at 11:52 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> > Kees Cook <keescook@chromium.org> writes:
> >
> >> diff --git a/mm/usercopy.c b/mm/usercopy.c
> >> new file mode 100644
> >> index 000000000000..e4bf4e7ccdf6
> >> --- /dev/null
> >> +++ b/mm/usercopy.c
> >> @@ -0,0 +1,234 @@
> > ...
> >> +
> >> +/*
> >> + * Checks if a given pointer and length is contained by the current
> >> + * stack frame (if possible).
> >> + *
> >> + * 0: not at all on the stack
> >> + * 1: fully within a valid stack frame
> >> + * 2: fully on the stack (when can't do frame-checking)
> >> + * -1: error condition (invalid stack position or bad stack frame)
> >> + */
> >> +static noinline int check_stack_object(const void *obj, unsigned long len)
> >> +{
> >> + const void * const stack = task_stack_page(current);
> >> + const void * const stackend = stack + THREAD_SIZE;
> >
> > That allows access to the entire stack, including the struct thread_info,
> > is that what we want - it seems dangerous? Or did I miss a check
> > somewhere else?
>
> That seems like a nice improvement to make, yeah.
>
> > We have end_of_stack() which computes the end of the stack taking
> > thread_info into account (end being the opposite of your end above).
>
> Amusingly, the object_is_on_stack() check in sched.h doesn't take
> thread_info into account either. :P Regardless, I think using
> end_of_stack() may not be best. To tighten the check, I think we could
> add this after checking that the object is on the stack:
>
> #ifdef CONFIG_STACK_GROWSUP
> stackend -= sizeof(struct thread_info);
> #else
> stack += sizeof(struct thread_info);
> #endif
>
> e.g. then if the pointer was in the thread_info, the second test would
> fail, triggering the protection.
FWIW, this won't work right on x86 after Andy's
CONFIG_THREAD_INFO_IN_TASK patches get merged.
--
Josh
next prev parent reply other threads:[~2016-07-22 17:46 UTC|newest]
Thread overview: 257+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-15 21:44 [PATCH v3 00/11] mm: Hardened usercopy Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 01/11] mm: Implement stack frame object validation Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 02/11] mm: Hardened usercopy Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-19 1:06 ` Laura Abbott
2016-07-19 1:06 ` [kernel-hardening] " Laura Abbott
2016-07-19 1:06 ` Laura Abbott
2016-07-19 1:06 ` Laura Abbott
2016-07-19 1:06 ` Laura Abbott
2016-07-19 1:06 ` Laura Abbott
2016-07-19 18:48 ` Kees Cook
2016-07-19 18:48 ` [kernel-hardening] " Kees Cook
2016-07-19 18:48 ` Kees Cook
2016-07-19 18:48 ` Kees Cook
2016-07-19 18:48 ` Kees Cook
2016-07-19 18:48 ` Kees Cook
2016-07-19 18:48 ` Kees Cook
2016-07-19 22:00 ` [PATCH] mm: Add is_migrate_cma_page Laura Abbott
2016-07-19 22:00 ` [kernel-hardening] " Laura Abbott
2016-07-19 22:00 ` Laura Abbott
2016-07-19 22:00 ` Laura Abbott
2016-07-19 22:00 ` Laura Abbott
2016-07-19 22:00 ` Laura Abbott
2016-07-19 22:40 ` Kees Cook
2016-07-19 22:40 ` [kernel-hardening] " Kees Cook
2016-07-19 22:40 ` Kees Cook
2016-07-19 22:40 ` Kees Cook
2016-07-19 22:40 ` Kees Cook
2016-07-19 22:40 ` Kees Cook
2016-07-19 22:40 ` Kees Cook
2016-07-20 10:24 ` [PATCH v3 02/11] mm: Hardened usercopy Balbir Singh
2016-07-20 10:24 ` [kernel-hardening] " Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 10:24 ` Balbir Singh
2016-07-20 15:36 ` Laura Abbott
2016-07-20 15:36 ` [kernel-hardening] " Laura Abbott
2016-07-20 15:36 ` Laura Abbott
2016-07-20 15:36 ` Laura Abbott
2016-07-20 15:36 ` Laura Abbott
2016-07-20 15:36 ` Laura Abbott
2016-07-20 15:36 ` Laura Abbott
2016-07-19 1:52 ` Laura Abbott
2016-07-19 1:52 ` [kernel-hardening] " Laura Abbott
2016-07-19 1:52 ` Laura Abbott
2016-07-19 1:52 ` Laura Abbott
2016-07-19 1:52 ` Laura Abbott
2016-07-19 1:52 ` Laura Abbott
2016-07-19 19:12 ` Kees Cook
2016-07-19 19:12 ` [kernel-hardening] " Kees Cook
2016-07-19 19:12 ` Kees Cook
2016-07-19 19:12 ` Kees Cook
2016-07-19 19:12 ` Kees Cook
2016-07-19 19:12 ` Kees Cook
2016-07-19 19:12 ` Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 22:55 ` [kernel-hardening] " Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 22:55 ` Kees Cook
2016-07-19 9:21 ` Christian Borntraeger
2016-07-19 9:21 ` [kernel-hardening] " Christian Borntraeger
2016-07-19 9:21 ` Christian Borntraeger
2016-07-19 9:21 ` Christian Borntraeger
2016-07-19 9:21 ` Christian Borntraeger
2016-07-19 9:21 ` Christian Borntraeger
2016-07-19 19:31 ` Kees Cook
2016-07-19 19:31 ` [kernel-hardening] " Kees Cook
2016-07-19 19:31 ` Kees Cook
2016-07-19 19:31 ` Kees Cook
2016-07-19 19:31 ` Kees Cook
2016-07-19 19:31 ` Kees Cook
2016-07-19 19:31 ` Kees Cook
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:14 ` [kernel-hardening] " Christian Borntraeger
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:14 ` Christian Borntraeger
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:34 ` [kernel-hardening] " Kees Cook
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:34 ` Kees Cook
2016-07-19 20:44 ` Christian Borntraeger
2016-07-19 20:44 ` [kernel-hardening] " Christian Borntraeger
2016-07-19 20:44 ` Christian Borntraeger
2016-07-19 20:44 ` Christian Borntraeger
2016-07-19 20:44 ` Christian Borntraeger
2016-07-19 20:44 ` Christian Borntraeger
2016-07-19 20:44 ` Christian Borntraeger
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` [kernel-hardening] " Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
2016-07-21 6:52 ` Michael Ellerman
[not found] ` <5790711f.2350420a.b4287.2cc0SMTPIN_ADDED_BROKEN@mx.google.com>
2016-07-21 18:34 ` Kees Cook
2016-07-21 18:34 ` [kernel-hardening] " Kees Cook
2016-07-21 18:34 ` Kees Cook
2016-07-21 18:34 ` Kees Cook
2016-07-21 18:34 ` Kees Cook
2016-07-21 18:34 ` Kees Cook
2016-07-21 18:34 ` Kees Cook
2016-07-22 17:45 ` Josh Poimboeuf [this message]
2016-07-22 17:45 ` [kernel-hardening] " Josh Poimboeuf
2016-07-22 17:45 ` Josh Poimboeuf
2016-07-22 17:45 ` Josh Poimboeuf
2016-07-22 17:45 ` Josh Poimboeuf
2016-07-22 17:45 ` Josh Poimboeuf
2016-07-22 17:45 ` Josh Poimboeuf
2016-07-25 9:27 ` David Laight
2016-07-25 9:27 ` [kernel-hardening] " David Laight
2016-07-25 9:27 ` David Laight
2016-07-25 9:27 ` David Laight
2016-07-25 9:27 ` David Laight
2016-07-25 9:27 ` David Laight
2016-07-25 9:27 ` David Laight
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` [kernel-hardening] " Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:09 ` Michael Ellerman
2016-07-26 2:03 ` Michael Ellerman
2016-07-26 2:03 ` [kernel-hardening] " Michael Ellerman
2016-07-26 2:03 ` Michael Ellerman
2016-07-26 2:03 ` Michael Ellerman
2016-07-26 4:46 ` Kees Cook
2016-07-26 4:46 ` [kernel-hardening] " Kees Cook
2016-07-26 4:46 ` Kees Cook
2016-07-26 4:46 ` Kees Cook
2016-07-26 4:46 ` Kees Cook
2016-07-26 4:46 ` Kees Cook
2016-07-26 4:46 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 03/11] x86/uaccess: Enable hardened usercopy Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 04/11] ARM: uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 05/11] arm64/uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 06/11] ia64/uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 07/11] powerpc/uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 08/11] sparc/uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 09/11] s390/uaccess: " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 10/11] mm: SLAB hardened usercopy support Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` [PATCH v3 11/11] mm: SLUB " Kees Cook
2016-07-15 21:44 ` [kernel-hardening] " Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-15 21:44 ` Kees Cook
2016-07-18 8:26 ` [PATCH v3 00/11] mm: Hardened usercopy Balbir Singh
2016-07-18 8:26 ` [kernel-hardening] " Balbir Singh
2016-07-18 8:26 ` Balbir Singh
2016-07-18 8:26 ` Balbir Singh
2016-07-18 8:26 ` Balbir Singh
2016-07-18 8:26 ` Balbir Singh
2016-07-18 8:26 ` Balbir Singh
2016-07-20 9:52 ` David Laight
2016-07-20 9:52 ` [kernel-hardening] " David Laight
2016-07-20 9:52 ` David Laight
2016-07-20 9:52 ` David Laight
2016-07-20 9:52 ` David Laight
2016-07-20 9:52 ` David Laight
2016-07-20 9:52 ` David Laight
2016-07-20 15:31 ` Kees Cook
2016-07-20 15:31 ` [kernel-hardening] " Kees Cook
2016-07-20 15:31 ` Kees Cook
2016-07-20 15:31 ` Kees Cook
2016-07-20 15:31 ` Kees Cook
2016-07-20 15:31 ` Kees Cook
2016-07-20 15:31 ` Kees Cook
2016-07-20 16:02 ` David Laight
2016-07-20 16:02 ` [kernel-hardening] " David Laight
2016-07-20 16:02 ` David Laight
2016-07-20 16:02 ` David Laight
2016-07-20 16:02 ` David Laight
2016-07-20 16:02 ` David Laight
2016-07-20 16:02 ` David Laight
2016-07-20 16:22 ` Rik van Riel
2016-07-20 16:22 ` [kernel-hardening] " Rik van Riel
2016-07-20 16:22 ` Rik van Riel
2016-07-20 16:22 ` Rik van Riel
2016-07-20 16:22 ` Rik van Riel
2016-07-20 16:22 ` Rik van Riel
2016-07-20 17:44 ` Kees Cook
2016-07-20 17:44 ` [kernel-hardening] " Kees Cook
2016-07-20 17:44 ` Kees Cook
2016-07-20 17:44 ` Kees Cook
2016-07-20 17:44 ` Kees Cook
2016-07-20 17:44 ` Kees Cook
2016-07-20 17:44 ` Kees Cook
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