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 --- usr/dummy-include/sys/ioctl.h | 0 usr/dummy-include/sys/socket.h | 12 ++++++++++++ usr/dummy-include/sys/time.h | 3 +++ usr/dummy-include/sys/types.h | 0 4 files changed, 15 insertions(+) create mode 100644 usr/dummy-include/sys/ioctl.h create mode 100644 usr/dummy-include/sys/socket.h create mode 100644 usr/dummy-include/sys/time.h create mode 100644 usr/dummy-include/sys/types.h (limited to 'usr/dummy-include/sys') diff --git a/usr/dummy-include/sys/ioctl.h b/usr/dummy-include/sys/ioctl.h new file mode 100644 index 000000000..e69de29bb diff --git a/usr/dummy-include/sys/socket.h b/usr/dummy-include/sys/socket.h new file mode 100644 index 000000000..748751f9e --- /dev/null +++ b/usr/dummy-include/sys/socket.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DUMMY_SYS_SOCKET_H +#define _DUMMY_SYS_SOCKET_H + +#include + +struct sockaddr { + __kernel_sa_family_t sa_family; /* address family, AF_xxx */ + char sa_data[14]; /* 14 bytes of protocol address */ +}; + +#endif /* _DUMMY_SYS_SOCKET_H */ diff --git a/usr/dummy-include/sys/time.h b/usr/dummy-include/sys/time.h new file mode 100644 index 000000000..9817b8afb --- /dev/null +++ b/usr/dummy-include/sys/time.h @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#include diff --git a/usr/dummy-include/sys/types.h b/usr/dummy-include/sys/types.h new file mode 100644 index 000000000..e69de29bb -- cgit v1.3.1