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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.