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 --- Documentation/netlink/specs/binder.yaml | 93 +++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 Documentation/netlink/specs/binder.yaml (limited to 'Documentation/netlink/specs/binder.yaml') diff --git a/Documentation/netlink/specs/binder.yaml b/Documentation/netlink/specs/binder.yaml new file mode 100644 index 000000000..0f0575ad1 --- /dev/null +++ b/Documentation/netlink/specs/binder.yaml @@ -0,0 +1,93 @@ +# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) +# +# Copyright 2025 Google LLC +# +--- +name: binder +protocol: genetlink +uapi-header: linux/android/binder_netlink.h +doc: Binder interface over generic netlink + +attribute-sets: + - + name: report + doc: | + Attributes included within a transaction failure report. The elements + correspond directly with the specific transaction that failed, along + with the error returned to the sender e.g. BR_DEAD_REPLY. + + attributes: + - + name: error + type: u32 + doc: The enum binder_driver_return_protocol returned to the sender. + - + name: context + type: string + doc: The binder context where the transaction occurred. + - + name: from-pid + type: u32 + doc: The PID of the sender process. + - + name: from-tid + type: u32 + doc: The TID of the sender thread. + - + name: to-pid + type: u32 + doc: | + The PID of the recipient process. This attribute may not be present + if the target could not be determined. + - + name: to-tid + type: u32 + doc: | + The TID of the recipient thread. This attribute may not be present + if the target could not be determined. + - + name: is-reply + type: flag + doc: When present, indicates the failed transaction is a reply. + - + name: flags + type: u32 + doc: The bitmask of enum transaction_flags from the transaction. + - + name: code + type: u32 + doc: The application-defined code from the transaction. + - + name: data-size + type: u32 + doc: The transaction payload size in bytes. + +operations: + list: + - + name: report + doc: | + A multicast event sent to userspace subscribers to notify them about + binder transaction failures. The generated report provides the full + details of the specific transaction that failed. The intention is for + programs to monitor these events and react to the failures as needed. + + attribute-set: report + mcgrp: report + event: + attributes: + - error + - context + - from-pid + - from-tid + - to-pid + - to-tid + - is-reply + - flags + - code + - data-size + +mcast-groups: + list: + - + name: report -- cgit v1.3.1