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 --- include/rdma/lag.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 include/rdma/lag.h (limited to 'include/rdma/lag.h') diff --git a/include/rdma/lag.h b/include/rdma/lag.h new file mode 100644 index 000000000..7c06ec9b2 --- /dev/null +++ b/include/rdma/lag.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ +/* + * Copyright (c) 2020 Mellanox Technologies. All rights reserved. + */ + +#ifndef _RDMA_LAG_H_ +#define _RDMA_LAG_H_ + +#include + +struct ib_device; +struct rdma_ah_attr; + +enum rdma_lag_flags { + RDMA_LAG_FLAGS_HASH_ALL_SLAVES = 1 << 0 +}; + +void rdma_lag_put_ah_roce_slave(struct net_device *xmit_slave); +struct net_device *rdma_lag_get_ah_roce_slave(struct ib_device *device, + struct rdma_ah_attr *ah_attr, + gfp_t flags); + +#endif /* _RDMA_LAG_H_ */ -- cgit v1.3.1