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


From: Alexander Shishkin <alexander.shish...@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.hun...@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shish...@linux.intel.com>
Acked-by: Peter Zijlstra <pet...@infradead.org>
Cc: Arnaldo Carvalho de Melo <a...@infradead.org>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Cc: vi...@deater.net
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@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))

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