CVE-2022-48713

/// Technical description

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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References