112 lines
4.1 KiB
Diff
112 lines
4.1 KiB
Diff
From b153f8e687bf0739b113445d3cfe029593e9484a Mon Sep 17 00:00:00 2001
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From: Andy Lutomirski <luto@kernel.org>
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Date: Mon, 4 Dec 2017 15:07:27 +0100
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Subject: [PATCH 157/241] x86/entry/64: Remove the SYSENTER stack canary
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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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Now that the SYSENTER stack has a guard page, there's no need for a canary
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to detect overflow after the fact.
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Signed-off-by: Andy Lutomirski <luto@kernel.org>
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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Reviewed-by: Borislav Petkov <bp@suse.de>
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Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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Cc: Borislav Petkov <bp@alien8.de>
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Cc: Borislav Petkov <bpetkov@suse.de>
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Cc: Brian Gerst <brgerst@gmail.com>
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Cc: Dave Hansen <dave.hansen@intel.com>
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Cc: Dave Hansen <dave.hansen@linux.intel.com>
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Cc: David Laight <David.Laight@aculab.com>
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Cc: Denys Vlasenko <dvlasenk@redhat.com>
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Cc: Eduardo Valentin <eduval@amazon.com>
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Cc: Greg KH <gregkh@linuxfoundation.org>
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Cc: H. Peter Anvin <hpa@zytor.com>
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Cc: Josh Poimboeuf <jpoimboe@redhat.com>
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Cc: Juergen Gross <jgross@suse.com>
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Cc: Linus Torvalds <torvalds@linux-foundation.org>
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Cc: Peter Zijlstra <peterz@infradead.org>
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Cc: Rik van Riel <riel@redhat.com>
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Cc: Will Deacon <will.deacon@arm.com>
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Cc: aliguori@amazon.com
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Cc: daniel.gruss@iaik.tugraz.at
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Cc: hughd@google.com
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Cc: keescook@google.com
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Link: https://lkml.kernel.org/r/20171204150606.572577316@linutronix.de
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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(cherry picked from commit 7fbbd5cbebf118a9e09f5453f686656a167c3d1c)
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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 8158adf795cb48be67891feacacc36d7a247afdf)
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Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
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---
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arch/x86/include/asm/processor.h | 1 -
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arch/x86/kernel/dumpstack.c | 3 +--
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arch/x86/kernel/process.c | 1 -
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arch/x86/kernel/traps.c | 7 -------
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4 files changed, 1 insertion(+), 11 deletions(-)
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diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
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index 1bfe4bad797a..4737d378d7b5 100644
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--- a/arch/x86/include/asm/processor.h
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+++ b/arch/x86/include/asm/processor.h
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@@ -335,7 +335,6 @@ struct tss_struct {
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* Space for the temporary SYSENTER stack, used for SYSENTER
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* and the entry trampoline as well.
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*/
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- unsigned long SYSENTER_stack_canary;
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unsigned long SYSENTER_stack[64];
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/*
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diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
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index c1f503673f1e..c32c6cce9dcc 100644
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--- a/arch/x86/kernel/dumpstack.c
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+++ b/arch/x86/kernel/dumpstack.c
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@@ -48,8 +48,7 @@ bool in_sysenter_stack(unsigned long *stack, struct stack_info *info)
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int cpu = smp_processor_id();
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struct tss_struct *tss = &get_cpu_entry_area(cpu)->tss;
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- /* Treat the canary as part of the stack for unwinding purposes. */
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- void *begin = &tss->SYSENTER_stack_canary;
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+ void *begin = &tss->SYSENTER_stack;
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void *end = (void *)&tss->SYSENTER_stack + sizeof(tss->SYSENTER_stack);
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if ((void *)stack < begin || (void *)stack >= end)
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diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
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index 407fc37a8718..ec758390d24e 100644
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--- a/arch/x86/kernel/process.c
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+++ b/arch/x86/kernel/process.c
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@@ -80,7 +80,6 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = {
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*/
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.io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 },
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#endif
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- .SYSENTER_stack_canary = STACK_END_MAGIC,
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};
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EXPORT_PER_CPU_SYMBOL(cpu_tss);
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diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
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index fd4d47e8672e..2818c83892b3 100644
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--- a/arch/x86/kernel/traps.c
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+++ b/arch/x86/kernel/traps.c
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@@ -826,13 +826,6 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
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debug_stack_usage_dec();
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exit:
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- /*
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- * This is the most likely code path that involves non-trivial use
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- * of the SYSENTER stack. Check that we haven't overrun it.
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- */
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- WARN(this_cpu_read(cpu_tss.SYSENTER_stack_canary) != STACK_END_MAGIC,
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- "Overran or corrupted SYSENTER stack\n");
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-
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ist_exit(regs);
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}
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NOKPROBE_SYMBOL(do_debug);
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--
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2.14.2
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