This is a note to let you know that I've just added the patch titled
x86/cpufeatures: Add X86_BUG_CPU_INSECURE
to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-cpufeatures-add-x86_bug_cpu_insecure.patch and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From a89f040fa34ec9cd682aed98b8f04e3c47d998bd Mon Sep 17 00:00:00 2001
From: Thomas Gleixner tglx@linutronix.de Date: Mon, 4 Dec 2017 15:07:33 +0100 Subject: x86/cpufeatures: Add X86_BUG_CPU_INSECURE
From: Thomas Gleixner tglx@linutronix.de
commit a89f040fa34ec9cd682aed98b8f04e3c47d998bd upstream.
Many x86 CPUs leak information to user space due to missing isolation of user space and kernel space page tables. There are many well documented ways to exploit that.
The upcoming software migitation of isolating the user and kernel space page tables needs a misfeature flag so code can be made runtime conditional.
Add the BUG bits which indicates that the CPU is affected and add a feature bit which indicates that the software migitation is enabled.
Assume for now that _ALL_ x86 CPUs are affected by this. Exceptions can be made later.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andy Lutomirski luto@kernel.org Cc: Boris Ostrovsky boris.ostrovsky@oracle.com Cc: Borislav Petkov bp@alien8.de Cc: Brian Gerst brgerst@gmail.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Laight David.Laight@aculab.com Cc: Denys Vlasenko dvlasenk@redhat.com Cc: Eduardo Valentin eduval@amazon.com Cc: Greg KH gregkh@linuxfoundation.org Cc: H. Peter Anvin hpa@zytor.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Juergen Gross jgross@suse.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Will Deacon will.deacon@arm.com Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/common.c | 4 ++++ 2 files changed, 5 insertions(+)
--- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -277,6 +277,7 @@ #define X86_BUG_FXSAVE_LEAK X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */ #define X86_BUG_CLFLUSH_MONITOR X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */ #define X86_BUG_SYSRET_SS_ATTRS X86_BUG(8) /* SYSRET doesn't fix up SS attrs */ +#define X86_BUG_CPU_INSECURE X86_BUG(14) /* CPU is insecure and needs kernel page table isolation */
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
--- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -830,6 +830,10 @@ static void __init early_identify_cpu(st }
setup_force_cpu_cap(X86_FEATURE_ALWAYS); + + /* Assume for now that ALL x86 CPUs are insecure */ + setup_force_cpu_bug(X86_BUG_CPU_INSECURE); + fpu__init_system(c); }
Patches currently in stable-queue which might be from tglx@linutronix.de are
queue-4.4/x86-mm-pat-dev-mem-remove-superfluous-error-message.patch queue-4.4/x86-cpufeatures-add-x86_bug_spectre_v.patch queue-4.4/x86-microcode-intel-extend-bdw-late-loading-with-a-revision-check.patch queue-4.4/x86-alternatives-add-missing-n-at-end-of-alternative-inline-asm.patch queue-4.4/sysfs-cpu-fix-typos-in-vulnerability-documentation.patch queue-4.4/locking-mutex-allow-next-waiter-lockless-wakeup.patch queue-4.4/x86-cpufeatures-add-x86_bug_cpu_insecure.patch queue-4.4/x86-cpufeatures-make-cpu-bugs-sticky.patch queue-4.4/x86-vsdo-fix-build-on-paravirt_clock-y-kvm_guest-n.patch queue-4.4/x86-pti-efi-broken-conversion-from-efi-to-kernel-page-table.patch queue-4.4/x86-documentation-add-pti-description.patch queue-4.4/x86-acpi-handle-sci-interrupts-above-legacy-space-gracefully.patch queue-4.4/x86-cpu-implement-cpu-vulnerabilites-sysfs-functions.patch queue-4.4/futex-replace-barrier-in-unqueue_me-with-read_once.patch queue-4.4/x86-cpu-factor-out-application-of-forced-cpu-caps.patch queue-4.4/selftests-x86-add-test_vsyscall.patch queue-4.4/x86-cpu-merge-bugs.c-and-bugs_64.c.patch queue-4.4/sysfs-cpu-add-vulnerability-folder.patch queue-4.4/x86-pti-rename-bug_cpu_insecure-to-bug_cpu_meltdown.patch queue-4.4/x86-acpi-reduce-code-duplication-in-mp_override_legacy_irq.patch queue-4.4/x86-alternatives-fix-optimize_nops-checking.patch