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/frmr_pools.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 include/rdma/frmr_pools.h (limited to 'include/rdma/frmr_pools.h') diff --git a/include/rdma/frmr_pools.h b/include/rdma/frmr_pools.h new file mode 100644 index 000000000..aed4d69d3 --- /dev/null +++ b/include/rdma/frmr_pools.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB + * + * Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved. + */ + +#ifndef FRMR_POOLS_H +#define FRMR_POOLS_H + +#include +#include + +struct ib_device; +struct ib_mr; + +struct ib_frmr_key { + u64 vendor_key; + /* A pool with non-zero kernel_vendor_key is a kernel-only pool. */ + u64 kernel_vendor_key; + size_t num_dma_blocks; + int access_flags; + u8 ats:1; +}; + +struct ib_frmr_pool_ops { + int (*create_frmrs)(struct ib_device *device, struct ib_frmr_key *key, + u32 *handles, u32 count); + void (*destroy_frmrs)(struct ib_device *device, u32 *handles, + u32 count); + int (*build_key)(struct ib_device *device, const struct ib_frmr_key *in, + struct ib_frmr_key *out); +}; + +int ib_frmr_pools_init(struct ib_device *device, + const struct ib_frmr_pool_ops *pool_ops); +void ib_frmr_pools_cleanup(struct ib_device *device); +int ib_frmr_pool_pop(struct ib_device *device, struct ib_mr *mr); +void ib_frmr_pool_push(struct ib_device *device, struct ib_mr *mr); +void ib_frmr_pool_drop(struct ib_mr *mr); + +#endif /* FRMR_POOLS_H */ -- cgit v1.3.1