CVE-2026-98937perf/core: Check kernel access when kernel callchains are requested

Official description

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/132bee76097be421ab3012130b5b506324cf2be1
• https://git.kernel.org/stable/c/2581b43e162cfc43e6f5d8dd8d2b38f3441550de
• https://git.kernel.org/stable/c/6e187281f978a2bff98ead6aa40f8ddc9a2c9afb
• https://git.kernel.org/stable/c/a4573a3838ae4fc73b70019cfa1dac9aaea7cc2f