Commit-ID: ddfdad991e55b65c1cc4ee29502f6dceee04455a Gitweb: http://git.kernel.org/tip/ddfdad991e55b65c1cc4ee29502f6dceee04455a Author: Alexander Shishkin <alexander.shish...@linux.intel.com> AuthorDate: Thu, 15 Sep 2016 18:13:51 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 16 Sep 2016 11:14:16 +0200
perf/x86/intel/pt: Fix kernel address filter's offset validation 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: sta...@vger.kernel.org # v4.7 Cc: sta...@vger.kernel.org#v4.7 Cc: vi...@deater.net Link: http://lkml.kernel.org/r/20160915151352.21306-3-alexander.shish...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/events/intel/pt.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 5ec0100..1f94963 100644 --- 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 perf_event *event) 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_validate(struct list_head *filters) 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))
