Patch "perf/x86/intel/pt: Fix kernel address filter's offset validation" has been added to the 4.7-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    perf/x86/intel/pt: Fix kernel address filter's offset validation

to the 4.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-x86-intel-pt-fix-kernel-address-filter-s-offset-validation.patch
and it can be found in the queue-4.7 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 ddfdad991e55b65c1cc4ee29502f6dceee04455a Mon Sep 17 00:00:00 2001
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: Thu, 15 Sep 2016 18:13:51 +0300
Subject: perf/x86/intel/pt: Fix kernel address filter's offset validation

From: Alexander Shishkin <alexander.shishkin@linux.intel.com>

commit ddfdad991e55b65c1cc4ee29502f6dceee04455a upstream.

The kernel_ip() filter is used mostly by the DS/LBR code to look at the
branch addresses, but Intel PT also uses it to validate the address
filter offsets for kernel addresses, for which it is not sufficient:
supplying something in bits 64:48 that's not a sign extension of the lower
address bits (like 0xf00d000000000000) throws a #GP.

This patch adds address validation for the user supplied kernel filters.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160915151352.21306-3-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/events/intel/pt.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -1074,6 +1074,11 @@ static void pt_addr_filters_fini(struct
 	event->hw.addr_filters = NULL;
 }
 
+static inline bool valid_kernel_ip(unsigned long ip)
+{
+	return virt_addr_valid(ip) && kernel_ip(ip);
+}
+
 static int pt_event_addr_filters_validate(struct list_head *filters)
 {
 	struct perf_addr_filter *filter;
@@ -1084,7 +1089,7 @@ static int pt_event_addr_filters_validat
 		if (!filter->range || !filter->size)
 			return -EOPNOTSUPP;
 
-		if (!filter->inode && !kernel_ip(filter->offset))
+		if (!filter->inode && !valid_kernel_ip(filter->offset))
 			return -EINVAL;
 
 		if (++range > pt_cap_get(PT_CAP_num_address_ranges))


Patches currently in stable-queue which might be from alexander.shishkin@linux.intel.com are

queue-4.7/perf-x86-intel-pt-fix-an-off-by-one-in-address-filter-configuration.patch
queue-4.7/perf-x86-intel-fix-pebsv3-record-drain.patch
queue-4.7/perf-x86-intel-pt-do-validate-the-size-of-a-kernel-address-filter.patch
queue-4.7/perf-x86-intel-pt-fix-kernel-address-filter-s-offset-validation.patch