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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 12:23:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-08 12:23:00 -0700
commit223cea6a4f0552b86fb25e3b8bbd00469816cd7a (patch)
treeb1470f93d7b9b996634f1be7fbee2d924aba6f0d
parent2f0f6503e37551eb8d8d5e4d27c78d28a30fed5a (diff)
parent993773d11d45c90cb1c6481c2638c3d9f092ea5b (diff)
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner: "The speculative paranoia departement delivers a few more plugs for possible (probably theoretical) spectre/mds leaks" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/tls: Fix possible spectre-v1 in do_get_thread_area() x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg() x86/speculation/mds: Eliminate leaks by trace_hardirqs_on()
-rw-r--r--arch/x86/include/asm/mwait.h4
-rw-r--r--arch/x86/kernel/ptrace.c4
-rw-r--r--arch/x86/kernel/tls.c9
3 files changed, 12 insertions, 5 deletions
diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h
index eb0f80ce8524..e28f8b723b5c 100644
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -86,9 +86,9 @@ static inline void __mwaitx(unsigned long eax, unsigned long ebx,
static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
{
- mds_idle_clear_cpu_buffers();
-
trace_hardirqs_on();
+
+ mds_idle_clear_cpu_buffers();
/* "mwait %eax, %ecx;" */
asm volatile("sti; .byte 0x0f, 0x01, 0xc9;"
:: "a" (eax), "c" (ecx));
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 53f34121fdca..ee9099061d01 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -25,6 +25,7 @@
#include <linux/rcupdate.h>
#include <linux/export.h>
#include <linux/context_tracking.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
@@ -635,7 +636,8 @@ static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
unsigned long val = 0;
if (n < HBP_NUM) {
- struct perf_event *bp = thread->ptrace_bps[n];
+ int index = array_index_nospec(n, HBP_NUM);
+ struct perf_event *bp = thread->ptrace_bps[index];
if (bp)
val = bp->hw.info.address;
diff --git a/arch/x86/kernel/tls.c b/arch/x86/kernel/tls.c
index a5b802a12212..71d3fef1edc9 100644
--- a/arch/x86/kernel/tls.c
+++ b/arch/x86/kernel/tls.c
@@ -5,6 +5,7 @@
#include <linux/user.h>
#include <linux/regset.h>
#include <linux/syscalls.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
#include <asm/desc.h>
@@ -220,6 +221,7 @@ int do_get_thread_area(struct task_struct *p, int idx,
struct user_desc __user *u_info)
{
struct user_desc info;
+ int index;
if (idx == -1 && get_user(idx, &u_info->entry_number))
return -EFAULT;
@@ -227,8 +229,11 @@ int do_get_thread_area(struct task_struct *p, int idx,
if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
return -EINVAL;
- fill_user_desc(&info, idx,
- &p->thread.tls_array[idx - GDT_ENTRY_TLS_MIN]);
+ index = idx - GDT_ENTRY_TLS_MIN;
+ index = array_index_nospec(index,
+ GDT_ENTRY_TLS_MAX - GDT_ENTRY_TLS_MIN + 1);
+
+ fill_user_desc(&info, idx, &p->thread.tls_array[index]);
if (copy_to_user(u_info, &info, sizeof(info)))
return -EFAULT;