Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Check kernel access when kernel callchains are requested
perf_event_open() currently gates perf_allow_kernel() only on !attr.exclude_kernel.
However, users can still request kernel callchain collection with attr.exclude_callchain_kernel == 0 even when attr.exclude_kernel == 1. That still requires kernel profiling privilege, but the existing check does not enforce it.
Update the permission check to call perf_allow_kernel() when either kernel sampling is requested or kernel callchains are requested.
This keeps permission checks aligned with requested data and prevents unprivileged use of kernel callchain capture.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 4.19.0 (+19 more)