From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, vince@deater.net, eranian@google.com, Arnaldo Carvalho de Melo , Alexander Shishkin , stable@vger.kernel.org#v4.7 Subject: [PATCH v1 3/3] perf/x86/intel/pt: Do validate the size of a kernel address filter Date: Thu, 15 Sep 2016 18:13:52 +0300 Message-Id: <20160915151352.21306-4-alexander.shishkin@linux.intel.com> In-Reply-To: <20160915151352.21306-1-alexander.shishkin@linux.intel.com> References: <20160915151352.21306-1-alexander.shishkin@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 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 # v4.7 Reported-by: Adrian Hunter Signed-off-by: Alexander Shishkin --- 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 1f94963a28..861a7d9cb6 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1089,8 +1089,13 @@ static int pt_event_addr_filters_validate(struct list_head *filters) if (!filter->range || !filter->size) return -EOPNOTSUPP; - if (!filter->inode && !valid_kernel_ip(filter->offset)) - return -EINVAL; + if (!filter->inode) { + if (!valid_kernel_ip(filter->offset)) + return -EINVAL; + + if (!valid_kernel_ip(filter->offset + filter->size)) + return -EINVAL; + } if (++range > pt_cap_get(PT_CAP_num_address_ranges)) return -EOPNOTSUPP; -- 2.9.3