From: Kees Cook <keescook@chromium.org> To: Thomas Garnier <thgarnie@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com>, "Brian Gerst" <brgerst@gmail.com>, "Herbert Xu" <herbert@gondor.apana.org.au>, "David S . Miller" <davem@davemloft.net>, "Thomas Gleixner" <tglx@linutronix.de>, "Ingo Molnar" <mingo@redhat.com>, "Peter Zijlstra" <peterz@infradead.org>, "Josh Poimboeuf" <jpoimboe@redhat.com>, "Arnd Bergmann" <arnd@arndb.de>, "Matthias Kaehlcke" <mka@chromium.org>, "Boris Ostrovsky" <boris.ostrovsky@oracle.com>, "Juergen Gross" <jgross@suse.com>, "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com>, "Joerg Roedel" <joro@8bytes.org>, "Andy Lutomirski" <luto@kernel.org>, "Borislav Petkov" <bp@alien8.de>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, "Borislav Petkov" <bp@suse.de>, "Christian Borntraeger" <borntraeger@de.ibm.com>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, "Len Brown" <len.brown@intel.com>, "Pavel Machek" <pavel@ucw.cz> Subject: Re: [RFC 16/22] x86/percpu: Adapt percpu for PIE support Date: Wed, 2 Aug 2017 09:56:32 -0700 [thread overview] Message-ID: <CAGXu5jLhg5d0rxkfTGDjNxcsqd9BH8BSOPEOn=PBKx_dYeq8ow@mail.gmail.com> (raw) In-Reply-To: <CAJcbSZF5-gVg=Q6yAV2ymHo+SC6Go=vQHXMR0UTdKH2Jbe-s-g@mail.gmail.com> On Wed, Aug 2, 2017 at 9:42 AM, Thomas Garnier <thgarnie@google.com> wrote: > I noticed that not only we have the problem of gs:0x40 not being > accessible. The compiler will default to the fs register if > mcmodel=kernel is not set. > > On the next patch set, I am going to add support for > -mstack-protector-guard=global so a global variable can be used > instead of the segment register. Similar approach than ARM/ARM64. While this is probably understood, I have to point out that this would be a major regression for the stack protection on x86. > Following this patch, I will work with gcc and llvm to add > -mstack-protector-reg=<segment register> support similar to PowerPC. > This way we can have gs used even without mcmodel=kernel. Once that's > an option, I can setup the GDT as described in the previous email > (similar to RFG). It would be much nicer if we could teach gcc about the percpu area instead. This would let us solve the global stack protector problem on the other architectures: http://www.openwall.com/lists/kernel-hardening/2017/06/27/6 -Kees -- Kees Cook Pixel Security
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org> To: Thomas Garnier <thgarnie@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com>, "Brian Gerst" <brgerst@gmail.com>, "Herbert Xu" <herbert@gondor.apana.org.au>, "David S . Miller" <davem@davemloft.net>, "Thomas Gleixner" <tglx@linutronix.de>, "Ingo Molnar" <mingo@redhat.com>, "Peter Zijlstra" <peterz@infradead.org>, "Josh Poimboeuf" <jpoimboe@redhat.com>, "Arnd Bergmann" <arnd@arndb.de>, "Matthias Kaehlcke" <mka@chromium.org>, "Boris Ostrovsky" <boris.ostrovsky@oracle.com>, "Juergen Gross" <jgross@suse.com>, "Paolo Bonzini" <pbonzini@redhat.com>, "Radim Krčmář" <rkrcmar@redhat.com>, "Joerg Roedel" <joro@8bytes.org>, "Andy Lutomirski" <luto@kernel.org>, "Borislav Petkov" <bp@alien8.de>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, "Borislav Petkov" <bp@suse.de>, "Christian Borntraeger" <borntraeger@de.ibm.com>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, "Len Brown" <len.brown@intel.com>, "Pavel Machek" <pavel@ucw.cz>, "Tejun Heo" <tj@kernel.org>, "Christoph Lameter" <cl@linux.com>, "Paul Gortmaker" <paul.gortmaker@windriver.com>, "Chris Metcalf" <cmetcalf@mellanox.com>, "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>, "Andrew Morton" <akpm@linux-foundation.org>, "Christopher Li" <sparse@chrisli.org>, "Dou Liyang" <douly.fnst@cn.fujitsu.com>, "Masahiro Yamada" <yamada.masahiro@socionext.com>, "Daniel Borkmann" <daniel@iogearbox.net>, "Markus Trippelsdorf" <markus@trippelsdorf.de>, "Peter Foley" <pefoley2@pefoley.com>, "Steven Rostedt" <rostedt@goodmis.org>, "Tim Chen" <tim.c.chen@linux.intel.com>, "Ard Biesheuvel" <ard.biesheuvel@linaro.org>, "Catalin Marinas" <catalin.marinas@arm.com>, "Matthew Wilcox" <mawilcox@microsoft.com>, "Michal Hocko" <mhocko@suse.com>, "Rob Landley" <rob@landley.net>, "Jiri Kosina" <jkosina@suse.cz>, "H . J . Lu" <hjl.tools@gmail.com>, "Paul Bolle" <pebolle@tiscali.nl>, "Baoquan He" <bhe@redhat.com>, "Daniel Micay" <danielmicay@gmail.com>, "the arch/x86 maintainers" <x86@kernel.org>, "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>, "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>, xen-devel@lists.xenproject.org, "kvm list" <kvm@vger.kernel.org>, linux-pm <linux-pm@vger.kernel.org>, linux-arch <linux-arch@vger.kernel.org>, linux-sparse@vger.kernel.org, "Kernel Hardening" <kernel-hardening@lists.openwall.com> Subject: [kernel-hardening] Re: [RFC 16/22] x86/percpu: Adapt percpu for PIE support Date: Wed, 2 Aug 2017 09:56:32 -0700 [thread overview] Message-ID: <CAGXu5jLhg5d0rxkfTGDjNxcsqd9BH8BSOPEOn=PBKx_dYeq8ow@mail.gmail.com> (raw) In-Reply-To: <CAJcbSZF5-gVg=Q6yAV2ymHo+SC6Go=vQHXMR0UTdKH2Jbe-s-g@mail.gmail.com> On Wed, Aug 2, 2017 at 9:42 AM, Thomas Garnier <thgarnie@google.com> wrote: > I noticed that not only we have the problem of gs:0x40 not being > accessible. The compiler will default to the fs register if > mcmodel=kernel is not set. > > On the next patch set, I am going to add support for > -mstack-protector-guard=global so a global variable can be used > instead of the segment register. Similar approach than ARM/ARM64. While this is probably understood, I have to point out that this would be a major regression for the stack protection on x86. > Following this patch, I will work with gcc and llvm to add > -mstack-protector-reg=<segment register> support similar to PowerPC. > This way we can have gs used even without mcmodel=kernel. Once that's > an option, I can setup the GDT as described in the previous email > (similar to RFG). It would be much nicer if we could teach gcc about the percpu area instead. This would let us solve the global stack protector problem on the other architectures: http://www.openwall.com/lists/kernel-hardening/2017/06/27/6 -Kees -- Kees Cook Pixel Security
next prev parent reply other threads:[~2017-08-02 16:56 UTC|newest] Thread overview: 151+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-07-18 22:33 x86: PIE support and option to extend KASLR randomization Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 01/22] x86/crypto: Adapt assembly for PIE support Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` Thomas Garnier 2017-07-18 22:33 ` [RFC 02/22] x86: Use symbol name on bug table " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 03/22] x86: Use symbol name in jump " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 04/22] x86: Add macro to get symbol address " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 05/22] xen: Adapt assembly " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 06/22] kvm: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 2:49 ` Brian Gerst 2017-07-19 2:49 ` Brian Gerst 2017-07-19 2:49 ` [kernel-hardening] " Brian Gerst 2017-07-19 15:40 ` Thomas Garnier 2017-07-19 15:40 ` [kernel-hardening] " Thomas Garnier 2017-07-19 22:27 ` H. Peter Anvin 2017-07-19 22:27 ` H. Peter Anvin 2017-07-19 22:27 ` [kernel-hardening] " H. Peter Anvin 2017-07-19 22:44 ` Thomas Garnier 2017-07-19 22:44 ` [kernel-hardening] " Thomas Garnier 2017-07-19 22:44 ` Thomas Garnier 2017-07-19 22:58 ` Ard Biesheuvel 2017-07-19 22:58 ` Ard Biesheuvel 2017-07-19 22:58 ` [kernel-hardening] " Ard Biesheuvel 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 23:47 ` H. Peter Anvin 2017-07-19 15:40 ` Thomas Garnier 2017-07-18 22:33 ` [RFC 07/22] x86: relocate_kernel - " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 22:58 ` H. Peter Anvin 2017-07-19 22:58 ` H. Peter Anvin 2017-07-19 22:58 ` [kernel-hardening] " H. Peter Anvin 2017-07-19 23:23 ` Thomas Garnier 2017-07-19 23:23 ` [kernel-hardening] " Thomas Garnier 2017-07-19 23:23 ` Thomas Garnier 2017-07-18 22:33 ` [RFC 08/22] x86/entry/64: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 09/22] x86: pm-trace - " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 10/22] x86/CPU: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 11/22] x86/acpi: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 12/22] x86/boot/64: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 13/22] x86/power/64: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 18:41 ` Pavel Machek 2017-07-19 18:41 ` [kernel-hardening] " Pavel Machek 2017-07-19 18:41 ` Pavel Machek 2017-07-18 22:33 ` [RFC 14/22] x86/paravirt: " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 15/22] x86/boot/64: Use _text in a global " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 16/22] x86/percpu: Adapt percpu " Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 3:08 ` Brian Gerst 2017-07-19 3:08 ` [kernel-hardening] " Brian Gerst 2017-07-19 18:26 ` Thomas Garnier 2017-07-19 18:26 ` Thomas Garnier 2017-07-19 18:26 ` [kernel-hardening] " Thomas Garnier 2017-07-19 23:33 ` H. Peter Anvin 2017-07-19 23:33 ` H. Peter Anvin 2017-07-19 23:33 ` [kernel-hardening] " H. Peter Anvin 2017-07-20 2:21 ` H. Peter Anvin 2017-07-20 2:21 ` H. Peter Anvin 2017-07-20 2:21 ` [kernel-hardening] " H. Peter Anvin 2017-07-20 3:03 ` H. Peter Anvin 2017-07-20 3:03 ` H. Peter Anvin 2017-07-20 3:03 ` [kernel-hardening] " H. Peter Anvin 2017-07-20 14:26 ` Thomas Garnier 2017-07-20 14:26 ` [kernel-hardening] " Thomas Garnier 2017-08-02 16:42 ` Thomas Garnier 2017-08-02 16:42 ` Thomas Garnier 2017-08-02 16:42 ` [kernel-hardening] " Thomas Garnier 2017-08-02 16:56 ` Kees Cook [this message] 2017-08-02 16:56 ` Kees Cook 2017-08-02 18:05 ` Thomas Garnier 2017-08-02 18:05 ` [kernel-hardening] " Thomas Garnier 2017-08-02 18:05 ` Thomas Garnier 2017-08-02 16:56 ` Kees Cook 2017-07-20 14:26 ` Thomas Garnier 2017-07-19 3:08 ` Brian Gerst 2017-07-18 22:33 ` [RFC 17/22] compiler: Option to default to hidden symbols Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 18/22] x86/relocs: Handle DYN relocations for PIE support Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 19/22] x86/pie: Add option to build the kernel as PIE for x86_64 Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-18 22:33 ` [RFC 20/22] x86/relocs: Add option to generate 64-bit relocations Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 22:33 ` H. Peter Anvin 2017-07-19 22:33 ` H. Peter Anvin 2017-07-19 22:33 ` [kernel-hardening] " H. Peter Anvin 2017-07-19 22:47 ` Thomas Garnier 2017-07-19 22:47 ` Thomas Garnier 2017-07-19 22:47 ` [kernel-hardening] " Thomas Garnier 2017-07-19 23:08 ` H. Peter Anvin 2017-07-19 23:08 ` [kernel-hardening] " H. Peter Anvin 2017-07-19 23:25 ` Thomas Garnier 2017-07-19 23:25 ` [kernel-hardening] " Thomas Garnier 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:45 ` H. Peter Anvin 2017-07-19 23:25 ` Thomas Garnier 2017-07-19 23:08 ` H. Peter Anvin 2017-07-18 22:33 ` [RFC 21/22] x86/module: Add support for mcmodel large and PLTs Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 1:35 ` H. Peter Anvin 2017-07-19 1:35 ` H. Peter Anvin 2017-07-19 1:35 ` [kernel-hardening] " H. Peter Anvin 2017-07-19 3:59 ` Brian Gerst 2017-07-19 3:59 ` Brian Gerst 2017-07-19 3:59 ` [kernel-hardening] " Brian Gerst 2017-07-19 15:58 ` Thomas Garnier 2017-07-19 15:58 ` Thomas Garnier 2017-07-19 15:58 ` [kernel-hardening] " Thomas Garnier 2017-07-19 17:34 ` Brian Gerst 2017-07-19 17:34 ` [kernel-hardening] " Brian Gerst 2017-07-24 16:32 ` Thomas Garnier 2017-07-24 16:32 ` [kernel-hardening] " Thomas Garnier 2017-07-24 16:32 ` Thomas Garnier 2017-07-19 17:34 ` Brian Gerst 2017-07-18 22:33 ` [RFC 22/22] x86/kaslr: Add option to extend KASLR range from 1GB to 3GB Thomas Garnier 2017-07-18 22:33 ` [kernel-hardening] " Thomas Garnier 2017-07-19 12:10 ` Baoquan He 2017-07-19 12:10 ` [kernel-hardening] " Baoquan He 2017-07-19 13:49 ` Baoquan He 2017-07-19 13:49 ` Baoquan He 2017-07-19 13:49 ` [kernel-hardening] " Baoquan He 2017-07-19 12:10 ` Baoquan He 2017-07-19 14:08 ` x86: PIE support and option to extend KASLR randomization Christopher Lameter 2017-07-19 14:08 ` [kernel-hardening] " Christopher Lameter 2017-07-19 19:21 ` Kees Cook 2017-07-19 19:21 ` Kees Cook 2017-07-19 19:21 ` [kernel-hardening] " Kees Cook 2017-07-19 14:08 ` Christopher Lameter
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