From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/misc/pvpanic/Kconfig | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 drivers/misc/pvpanic/Kconfig (limited to 'drivers/misc/pvpanic/Kconfig') diff --git a/drivers/misc/pvpanic/Kconfig b/drivers/misc/pvpanic/Kconfig new file mode 100644 index 000000000..12d40a21f --- /dev/null +++ b/drivers/misc/pvpanic/Kconfig @@ -0,0 +1,27 @@ +# SPDX-License-Identifier: GPL-2.0+ +# +# Pvpanic Kconfig +# +# Copyright (C) 2021 Oracle. +# + +config PVPANIC + bool "pvpanic device support" + help + This option allows to select a specific pvpanic device driver. + pvpanic is a paravirtualized device provided by QEMU; it lets + a virtual machine (guest) communicate panic events to the host. + +config PVPANIC_MMIO + tristate "pvpanic MMIO device support" + depends on HAS_IOMEM && (ACPI || OF) && PVPANIC + help + This driver provides support for the MMIO pvpanic device. + +config PVPANIC_PCI + tristate "pvpanic PCI device support" + depends on PCI && PVPANIC + help + This driver provides support for the PCI pvpanic device. + pvpanic is a paravirtualized device provided by QEMU which + forwards the panic events from the guest to the host. -- cgit v1.3.1