From: Dan Williams <dan.j.williams@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Elena Reshetova <elena.reshetova@intel.com>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Jonathan Corbet <corbet@lwn.net>,
x86@kernel.org, Russell King <linux@armlinux.org.uk>,
Ingo Molnar <mingo@redhat.com>, Andrew Honig <ahonig@google.com>,
alan@linux.intel.com, Tom Lendacky <thomas.lendacky@amd.com>,
Kees Cook <keescook@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Andy Lutomirski <luto@kernel.org>,
tglx@linutronix.de, akpm@linux-foundation.org,
Jim Mattson <jmattson@google.com>,
Christian Lamparter <chunkeey@gmail.com>,
gregkh@linuxfoundation.org, linux-wireless@vger.kernel.org,
stable@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Johannes Berg <johannes@sipsolutions.net>,
torvalds@linux-foundation.org,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH v4 00/10] prevent bounds-check bypass via speculative execution
Date: Thu, 18 Jan 2018 16:01:36 -0800 [thread overview]
Message-ID: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
Changes since v3 [1]
* Drop 'ifence_array_ptr' and associated compile-time + run-time
switching and just use the masking approach all the time.
* Convert 'get_user' to use pointer sanitization via masking rather than
lfence. '__get_user' and associated paths still rely on
lfence. (Linus)
"Basically, the rule is trivial: find all 'stac' users, and use
address masking if those users already integrate the limit
check, and lfence they don't."
* At syscall entry sanitize the syscall number under speculation
to remove a user controlled pointer de-reference in kernel
space. (Linus)
* Fix a raw lfence in the kvm code (added for v4.15-rc8) to use
'array_ptr'.
* Propose 'array_idx' as a way to sanitize user input that is
later used as an array index, but where the validation is
happening in a different code block than the array reference.
(Christian).
* Fix grammar in speculation.txt (Kees)
---
Quoting Mark's original RFC:
"Recently, Google Project Zero discovered several classes of attack
against speculative execution. One of these, known as variant-1, allows
explicit bounds checks to be bypassed under speculation, providing an
arbitrary read gadget. Further details can be found on the GPZ blog [2]
and the Documentation patch in this series."
A precondition of using this attack on the kernel is to get a user
controlled pointer de-referenced (under speculation) in privileged code.
The primary source of user controlled pointers in the kernel is the
arguments passed to 'get_user' and '__get_user'. An example of other
user controlled pointers are user-controlled array / pointer offsets.
Better tooling is needed to find more arrays / pointers with user
controlled indices / offsets that can be converted to use 'array_ptr' or
'array_idx'. A few are included in this set, and these are not expected
to be complete. That said, the 'get_user' protections raise the bar on
finding a vulnerable gadget in the kernel.
These patches are also available via the 'nospec-v4' git branch here:
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux nospec-v4
Note that the BPF fix for Spectre variant1 is merged for 4.15-rc8.
[2]: https://googleprojectzero.blogspot.co.uk/2018/01/reading-privileged-memory-with-side.html
---
Dan Williams (9):
asm/nospec, array_ptr: sanitize speculative array de-references
x86: implement array_ptr_mask()
x86: introduce __uaccess_begin_nospec and ifence
x86, __get_user: use __uaccess_begin_nospec
x86, get_user: use pointer masking to limit speculation
x86: narrow out of bounds syscalls to sys_read under speculation
vfs, fdtable: prevent bounds-check bypass via speculative execution
kvm, x86: fix spectre-v1 mitigation
nl80211: sanitize array index in parse_txq_params
Mark Rutland (1):
Documentation: document array_ptr
Documentation/speculation.txt | 143 +++++++++++++++++++++++++++++++++++++
arch/x86/entry/entry_64.S | 2 +
arch/x86/include/asm/barrier.h | 28 +++++++
arch/x86/include/asm/msr.h | 3 -
arch/x86/include/asm/smap.h | 24 ++++++
arch/x86/include/asm/uaccess.h | 15 +++-
arch/x86/include/asm/uaccess_32.h | 6 +-
arch/x86/include/asm/uaccess_64.h | 12 ++-
arch/x86/kvm/vmx.c | 19 ++---
arch/x86/lib/getuser.S | 5 +
arch/x86/lib/usercopy_32.c | 8 +-
include/linux/fdtable.h | 7 +-
include/linux/nospec.h | 65 +++++++++++++++++
net/wireless/nl80211.c | 10 ++-
14 files changed, 312 insertions(+), 35 deletions(-)
create mode 100644 Documentation/speculation.txt
create mode 100644 include/linux/nospec.h
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Elena Reshetova <elena.reshetova@intel.com>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Jonathan Corbet <corbet@lwn.net>,
x86@kernel.org, Russell King <linux@armlinux.org.uk>,
Ingo Molnar <mingo@redhat.com>, Andrew Honig <ahonig@google.com>,
alan@linux.intel.com, Tom Lendacky <thomas.lendacky@amd.com>,
Kees Cook <keescook@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Andy Lutomirski <luto@kernel.org>,
tglx@linutronix.de, akpm@linux-foundation.org,
Jim Mattson <jmattson@google.com>, Christian Lamparter <chunk>
Subject: [PATCH v4 00/10] prevent bounds-check bypass via speculative execution
Date: Thu, 18 Jan 2018 16:01:36 -0800 [thread overview]
Message-ID: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
Changes since v3 [1]
* Drop 'ifence_array_ptr' and associated compile-time + run-time
switching and just use the masking approach all the time.
* Convert 'get_user' to use pointer sanitization via masking rather than
lfence. '__get_user' and associated paths still rely on
lfence. (Linus)
"Basically, the rule is trivial: find all 'stac' users, and use
address masking if those users already integrate the limit
check, and lfence they don't."
* At syscall entry sanitize the syscall number under speculation
to remove a user controlled pointer de-reference in kernel
space. (Linus)
* Fix a raw lfence in the kvm code (added for v4.15-rc8) to use
'array_ptr'.
* Propose 'array_idx' as a way to sanitize user input that is
later used as an array index, but where the validation is
happening in a different code block than the array reference.
(Christian).
* Fix grammar in speculation.txt (Kees)
---
Quoting Mark's original RFC:
"Recently, Google Project Zero discovered several classes of attack
against speculative execution. One of these, known as variant-1, allows
explicit bounds checks to be bypassed under speculation, providing an
arbitrary read gadget. Further details can be found on the GPZ blog [2]
and the Documentation patch in this series."
A precondition of using this attack on the kernel is to get a user
controlled pointer de-referenced (under speculation) in privileged code.
The primary source of user controlled pointers in the kernel is the
arguments passed to 'get_user' and '__get_user'. An example of other
user controlled pointers are user-controlled array / pointer offsets.
Better tooling is needed to find more arrays / pointers with user
controlled indices / offsets that can be converted to use 'array_ptr' or
'array_idx'. A few are included in this set, and these are not expected
to be complete. That said, the 'get_user' protections raise the bar on
finding a vulnerable gadget in the kernel.
These patches are also available via the 'nospec-v4' git branch here:
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux nospec-v4
Note that the BPF fix for Spectre variant1 is merged for 4.15-rc8.
[2]: https://googleprojectzero.blogspot.co.uk/2018/01/reading-privileged-memory-with-side.html
---
Dan Williams (9):
asm/nospec, array_ptr: sanitize speculative array de-references
x86: implement array_ptr_mask()
x86: introduce __uaccess_begin_nospec and ifence
x86, __get_user: use __uaccess_begin_nospec
x86, get_user: use pointer masking to limit speculation
x86: narrow out of bounds syscalls to sys_read under speculation
vfs, fdtable: prevent bounds-check bypass via speculative execution
kvm, x86: fix spectre-v1 mitigation
nl80211: sanitize array index in parse_txq_params
Mark Rutland (1):
Documentation: document array_ptr
Documentation/speculation.txt | 143 +++++++++++++++++++++++++++++++++++++
arch/x86/entry/entry_64.S | 2 +
arch/x86/include/asm/barrier.h | 28 +++++++
arch/x86/include/asm/msr.h | 3 -
arch/x86/include/asm/smap.h | 24 ++++++
arch/x86/include/asm/uaccess.h | 15 +++-
arch/x86/include/asm/uaccess_32.h | 6 +-
arch/x86/include/asm/uaccess_64.h | 12 ++-
arch/x86/kvm/vmx.c | 19 ++---
arch/x86/lib/getuser.S | 5 +
arch/x86/lib/usercopy_32.c | 8 +-
include/linux/fdtable.h | 7 +-
include/linux/nospec.h | 65 +++++++++++++++++
net/wireless/nl80211.c | 10 ++-
14 files changed, 312 insertions(+), 35 deletions(-)
create mode 100644 Documentation/speculation.txt
create mode 100644 include/linux/nospec.h
WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Elena Reshetova <elena.reshetova@intel.com>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Jonathan Corbet <corbet@lwn.net>,
x86@kernel.org, Russell King <linux@armlinux.org.uk>,
Ingo Molnar <mingo@redhat.com>, Andrew Honig <ahonig@google.com>,
alan@linux.intel.com, Tom Lendacky <thomas.lendacky@amd.com>,
Kees Cook <keescook@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Andy Lutomirski <luto@kernel.org>,
tglx@linutronix.de, akpm@linux-foundation.org,
Jim Mattson <jmattson@google.com>,
Christian Lamparter <chunkeey@gmail.com>,
gregkh@linuxfoundation.org, linux-wireless@vger.kernel.org,
stable@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Johannes Berg <johannes@sipsolutions.net>,
torvalds@linux-foundation.org,
"David S. Miller" <davem@davemloft.net>
Subject: [kernel-hardening] [PATCH v4 00/10] prevent bounds-check bypass via speculative execution
Date: Thu, 18 Jan 2018 16:01:36 -0800 [thread overview]
Message-ID: <151632009605.21271.11304291057104672116.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
Changes since v3 [1]
* Drop 'ifence_array_ptr' and associated compile-time + run-time
switching and just use the masking approach all the time.
* Convert 'get_user' to use pointer sanitization via masking rather than
lfence. '__get_user' and associated paths still rely on
lfence. (Linus)
"Basically, the rule is trivial: find all 'stac' users, and use
address masking if those users already integrate the limit
check, and lfence they don't."
* At syscall entry sanitize the syscall number under speculation
to remove a user controlled pointer de-reference in kernel
space. (Linus)
* Fix a raw lfence in the kvm code (added for v4.15-rc8) to use
'array_ptr'.
* Propose 'array_idx' as a way to sanitize user input that is
later used as an array index, but where the validation is
happening in a different code block than the array reference.
(Christian).
* Fix grammar in speculation.txt (Kees)
---
Quoting Mark's original RFC:
"Recently, Google Project Zero discovered several classes of attack
against speculative execution. One of these, known as variant-1, allows
explicit bounds checks to be bypassed under speculation, providing an
arbitrary read gadget. Further details can be found on the GPZ blog [2]
and the Documentation patch in this series."
A precondition of using this attack on the kernel is to get a user
controlled pointer de-referenced (under speculation) in privileged code.
The primary source of user controlled pointers in the kernel is the
arguments passed to 'get_user' and '__get_user'. An example of other
user controlled pointers are user-controlled array / pointer offsets.
Better tooling is needed to find more arrays / pointers with user
controlled indices / offsets that can be converted to use 'array_ptr' or
'array_idx'. A few are included in this set, and these are not expected
to be complete. That said, the 'get_user' protections raise the bar on
finding a vulnerable gadget in the kernel.
These patches are also available via the 'nospec-v4' git branch here:
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux nospec-v4
Note that the BPF fix for Spectre variant1 is merged for 4.15-rc8.
[2]: https://googleprojectzero.blogspot.co.uk/2018/01/reading-privileged-memory-with-side.html
---
Dan Williams (9):
asm/nospec, array_ptr: sanitize speculative array de-references
x86: implement array_ptr_mask()
x86: introduce __uaccess_begin_nospec and ifence
x86, __get_user: use __uaccess_begin_nospec
x86, get_user: use pointer masking to limit speculation
x86: narrow out of bounds syscalls to sys_read under speculation
vfs, fdtable: prevent bounds-check bypass via speculative execution
kvm, x86: fix spectre-v1 mitigation
nl80211: sanitize array index in parse_txq_params
Mark Rutland (1):
Documentation: document array_ptr
Documentation/speculation.txt | 143 +++++++++++++++++++++++++++++++++++++
arch/x86/entry/entry_64.S | 2 +
arch/x86/include/asm/barrier.h | 28 +++++++
arch/x86/include/asm/msr.h | 3 -
arch/x86/include/asm/smap.h | 24 ++++++
arch/x86/include/asm/uaccess.h | 15 +++-
arch/x86/include/asm/uaccess_32.h | 6 +-
arch/x86/include/asm/uaccess_64.h | 12 ++-
arch/x86/kvm/vmx.c | 19 ++---
arch/x86/lib/getuser.S | 5 +
arch/x86/lib/usercopy_32.c | 8 +-
include/linux/fdtable.h | 7 +-
include/linux/nospec.h | 65 +++++++++++++++++
net/wireless/nl80211.c | 10 ++-
14 files changed, 312 insertions(+), 35 deletions(-)
create mode 100644 Documentation/speculation.txt
create mode 100644 include/linux/nospec.h
next reply other threads:[~2018-01-19 0:10 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-19 0:01 Dan Williams [this message]
2018-01-19 0:01 ` [kernel-hardening] [PATCH v4 00/10] prevent bounds-check bypass via speculative execution Dan Williams
2018-01-19 0:01 ` Dan Williams
2018-01-19 0:01 ` [PATCH v4 01/10] Documentation: document array_ptr Dan Williams
2018-01-19 0:01 ` [kernel-hardening] " Dan Williams
2018-01-19 0:01 ` [PATCH v4 02/10] asm/nospec, array_ptr: sanitize speculative array de-references Dan Williams
2018-01-19 0:01 ` [kernel-hardening] " Dan Williams
2018-01-19 10:20 ` Jann Horn
2018-01-19 17:48 ` Adam Sampson
2018-01-19 17:48 ` Adam Sampson
2018-01-19 17:48 ` Adam Sampson
2018-01-19 17:48 ` Adam Sampson
2018-01-19 18:12 ` Dan Williams
2018-01-19 18:18 ` Will Deacon
2018-01-19 18:18 ` Will Deacon
2018-01-19 18:26 ` [kernel-hardening] " Dan Williams
2018-01-19 18:18 ` Linus Torvalds
2018-01-19 18:18 ` Linus Torvalds
2018-01-19 20:55 ` [kernel-hardening] " Dan Williams
2018-01-25 7:09 ` Cyril Novikov
2018-01-25 7:09 ` [kernel-hardening] " Cyril Novikov
2018-01-25 22:37 ` Dan Williams
2018-01-25 22:37 ` [kernel-hardening] " Dan Williams
2018-01-19 0:01 ` [PATCH v4 03/10] x86: implement array_ptr_mask() Dan Williams
2018-01-19 0:01 ` [kernel-hardening] " Dan Williams
2018-01-19 0:01 ` [PATCH v4 04/10] x86: introduce __uaccess_begin_nospec and ifence Dan Williams
2018-01-19 0:01 ` [kernel-hardening] " Dan Williams
2018-01-19 0:02 ` [PATCH v4 05/10] x86, __get_user: use __uaccess_begin_nospec Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-19 0:02 ` [PATCH v4 06/10] x86, get_user: use pointer masking to limit speculation Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-19 0:02 ` [PATCH v4 07/10] x86: narrow out of bounds syscalls to sys_read under speculation Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-24 14:40 ` Jiri Slaby
2018-01-24 14:40 ` [kernel-hardening] " Jiri Slaby
2018-02-06 19:29 ` Luis Henriques
2018-02-06 19:48 ` Dan Williams
2018-02-06 20:26 ` Linus Torvalds
2018-02-06 20:37 ` Dan Williams
2018-02-06 20:42 ` Linus Torvalds
2018-02-06 20:43 ` Linus Torvalds
2018-02-06 20:49 ` Andy Lutomirski
2018-02-06 20:58 ` Linus Torvalds
2018-02-06 21:37 ` Dan Williams
2018-02-06 22:52 ` Linus Torvalds
2018-02-07 0:33 ` Dan Williams
2018-02-07 1:23 ` Linus Torvalds
2018-02-06 22:51 ` Luis Henriques
2018-02-06 22:51 ` Luis Henriques
2018-01-19 0:02 ` [PATCH v4 08/10] vfs, fdtable: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-19 0:02 ` [PATCH v4 09/10] kvm, x86: fix spectre-v1 mitigation Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-19 8:42 ` Paolo Bonzini
2018-01-19 8:42 ` [kernel-hardening] " Paolo Bonzini
2018-01-19 0:02 ` [PATCH v4 10/10] nl80211: sanitize array index in parse_txq_params Dan Williams
2018-01-19 0:02 ` [kernel-hardening] " Dan Williams
2018-01-19 0:02 ` Dan Williams
2018-01-21 10:37 ` Johannes Berg
2018-01-21 10:37 ` [kernel-hardening] " Johannes Berg
2018-01-21 10:37 ` Johannes Berg
2018-01-20 6:58 ` [PATCH v4 00/10] prevent bounds-check bypass via speculative execution Dan Williams
2018-01-20 6:58 ` [kernel-hardening] " Dan Williams
2018-01-20 6:58 ` Dan Williams
2018-01-20 16:56 ` Alexei Starovoitov
2018-01-20 16:56 ` [kernel-hardening] " Alexei Starovoitov
2018-01-20 16:56 ` Alexei Starovoitov
2018-01-20 17:07 ` Alexei Starovoitov
2018-01-20 17:07 ` [kernel-hardening] " Alexei Starovoitov
2018-01-20 17:07 ` Alexei Starovoitov
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