[PATCH 3/3] perf/x86/intel/pt: Do validate the size of a kernel address filter
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: 2016-09-15 13:36:51
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Subsystem:
performance events subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen
Right now, the kernel address filters in PT are prone to integer overflow that may happen in adding filter's size to its offset to obtain the end of the range. Such an overflow would also throw a #GP in the PT event configuration path. Fix this by explicitly validating the result of this calculation. Cc: stable@vger.kernel.org # 4.7 Reported-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> --- arch/x86/events/intel/pt.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 5ec0100e3f..834ce06b00 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c@@ -1084,8 +1084,13 @@ static int pt_event_addr_filters_validate(struct list_head *filters) if (!filter->range || !filter->size) return -EOPNOTSUPP; - if (!filter->inode && !kernel_ip(filter->offset)) - return -EINVAL; + if (!filter->inode) { + if (!kernel_ip(filter->offset)) + return -EINVAL; + + if (!kernel_ip(filter->offset + filter->size)) + return -EINVAL; + } if (++range > pt_cap_get(PT_CAP_num_address_ranges)) return -EOPNOTSUPP;
--
2.9.3