4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Zijlstra <pet...@infradead.org>

commit a5f81290ce475489fa2551c01a07470c1a4c932e upstream.

> arch/x86/events/intel/cstate.c:307 cstate_pmu_event_init() warn: potential 
> spectre issue 'pkg_msr' (local cap)

Userspace controls @attr, sanitize cfg (attr->config) before using it
to index an array.

Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: <sta...@kernel.org>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/x86/events/intel/cstate.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/events/intel/cstate.c
+++ b/arch/x86/events/intel/cstate.c
@@ -91,6 +91,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/perf_event.h>
+#include <linux/nospec.h>
 #include <asm/cpu_device_id.h>
 #include <asm/intel-family.h>
 #include "../perf_event.h"
@@ -301,6 +302,7 @@ static int cstate_pmu_event_init(struct
        } else if (event->pmu == &cstate_pkg_pmu) {
                if (cfg >= PERF_CSTATE_PKG_EVENT_MAX)
                        return -EINVAL;
+               cfg = array_index_nospec((unsigned long)cfg, 
PERF_CSTATE_PKG_EVENT_MAX);
                if (!pkg_msr[cfg].attr)
                        return -EINVAL;
                event->hw.event_base = pkg_msr[cfg].msr;


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