103 lines
3.9 KiB
Diff
103 lines
3.9 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
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Date: Fri, 27 Oct 2017 13:25:29 -0700
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Subject: [PATCH] x86/boot: Relocate definition of the initial state of CR0
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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CVE-2017-5754
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Both head_32.S and head_64.S utilize the same value to initialize the
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control register CR0. Also, other parts of the kernel might want to access
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this initial definition (e.g., emulation code for User-Mode Instruction
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Prevention uses this state to provide a sane dummy value for CR0 when
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emulating the smsw instruction). Thus, relocate this definition to a
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header file from which it can be conveniently accessed.
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Suggested-by: Borislav Petkov <bp@alien8.de>
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Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Borislav Petkov <bp@suse.de>
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Reviewed-by: Andy Lutomirski <luto@kernel.org>
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Cc: "Michael S. Tsirkin" <mst@redhat.com>
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Cc: Peter Zijlstra <peterz@infradead.org>
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Cc: Dave Hansen <dave.hansen@linux.intel.com>
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Cc: ricardo.neri@intel.com
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Cc: linux-mm@kvack.org
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Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
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Cc: Huang Rui <ray.huang@amd.com>
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Cc: Shuah Khan <shuah@kernel.org>
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Cc: linux-arch@vger.kernel.org
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Cc: Jonathan Corbet <corbet@lwn.net>
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Cc: Jiri Slaby <jslaby@suse.cz>
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Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
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Cc: Denys Vlasenko <dvlasenk@redhat.com>
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Cc: Chris Metcalf <cmetcalf@mellanox.com>
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Cc: Brian Gerst <brgerst@gmail.com>
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Cc: Josh Poimboeuf <jpoimboe@redhat.com>
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Cc: Chen Yucong <slaoub@gmail.com>
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Cc: Vlastimil Babka <vbabka@suse.cz>
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Cc: Dave Hansen <dave.hansen@intel.com>
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Cc: Andy Lutomirski <luto@amacapital.net>
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Cc: Masami Hiramatsu <mhiramat@kernel.org>
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Cc: Paolo Bonzini <pbonzini@redhat.com>
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Cc: Andrew Morton <akpm@linux-foundation.org>
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Cc: Linus Torvalds <torvalds@linux-foundation.org>
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Link: https://lkml.kernel.org/r/1509135945-13762-3-git-send-email-ricardo.neri-calderon@linux.intel.com
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(cherry picked from commit b0ce5b8c95c83a7b98c679b117e3d6ae6f97154b)
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Signed-off-by: Andy Whitcroft <apw@canonical.com>
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Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
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(cherry picked from commit 27c31a88c22edab269abe17c0ac7db0351d26c5f)
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Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
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---
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arch/x86/include/uapi/asm/processor-flags.h | 3 +++
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arch/x86/kernel/head_32.S | 3 ---
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arch/x86/kernel/head_64.S | 3 ---
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3 files changed, 3 insertions(+), 6 deletions(-)
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diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
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index 185f3d10c194..39946d0a1d41 100644
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--- a/arch/x86/include/uapi/asm/processor-flags.h
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+++ b/arch/x86/include/uapi/asm/processor-flags.h
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@@ -151,5 +151,8 @@
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#define CX86_ARR_BASE 0xc4
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#define CX86_RCR_BASE 0xdc
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+#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
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+ X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
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+ X86_CR0_PG)
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#endif /* _UAPI_ASM_X86_PROCESSOR_FLAGS_H */
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diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
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index 337a65377baf..7bbcdb1ea31a 100644
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--- a/arch/x86/kernel/head_32.S
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+++ b/arch/x86/kernel/head_32.S
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@@ -213,9 +213,6 @@ ENTRY(startup_32_smp)
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#endif
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.Ldefault_entry:
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-#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
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- X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
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- X86_CR0_PG)
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movl $(CR0_STATE & ~X86_CR0_PG),%eax
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movl %eax,%cr0
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diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
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index a2d8541b1da4..4117c1e0b3d2 100644
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--- a/arch/x86/kernel/head_64.S
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+++ b/arch/x86/kernel/head_64.S
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@@ -137,9 +137,6 @@ ENTRY(secondary_startup_64)
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1: wrmsr /* Make changes effective */
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/* Setup cr0 */
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-#define CR0_STATE (X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | \
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- X86_CR0_NE | X86_CR0_WP | X86_CR0_AM | \
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- X86_CR0_PG)
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movl $CR0_STATE, %eax
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/* Make changes effective */
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movq %rax, %cr0
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--
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2.14.2
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