CVE-2022-48713

In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel/pt: Fix crash with stop filters in single-range mode Add a
check for !buf->single before calling pt_buffer_region_size in a place
where a missing check can cause a kernel crash. Fixes a bug introduced by
commit 670638477aed (“perf/x86/intel/pt: Opportunistically use single range
output mode”), which added a support for PT single-range output mode. Since
that commit if a PT stop filter range is hit while tracing, the kernel will
crash because of a null pointer dereference in pt_handle_status due to
calling pt_buffer_region_size without a ToPA configured. The commit which
introduced single-range mode guarded almost all uses of the ToPA buffer
variables with checks of the buf->single variable, but missed the case
where tracing was stopped by the PT hardware, which happens when execution
hits a configured stop filter. Tested that hitting a stop filter while PT
recording successfully records a trace with this patch but crashes without
this patch.