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/net/espintcp.h | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 include/net/espintcp.h (limited to 'include/net/espintcp.h') diff --git a/include/net/espintcp.h b/include/net/espintcp.h new file mode 100644 index 000000000..c70efd704 --- /dev/null +++ b/include/net/espintcp.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_ESPINTCP_H +#define _NET_ESPINTCP_H + +#include +#include + +void __init espintcp_init(void); + +int espintcp_push_skb(struct sock *sk, struct sk_buff *skb); +int espintcp_queue_out(struct sock *sk, struct sk_buff *skb); +bool tcp_is_ulp_esp(struct sock *sk); + +struct espintcp_msg { + struct sk_buff *skb; + struct sk_msg skmsg; + int offset; + int len; +}; + +struct espintcp_ctx { + struct strparser strp; + struct sk_buff_head ike_queue; + struct sk_buff_head out_queue; + struct espintcp_msg partial; + void (*saved_data_ready)(struct sock *sk); + void (*saved_write_space)(struct sock *sk); + void (*saved_destruct)(struct sock *sk); + struct work_struct work; + bool tx_running; +}; + +static inline struct espintcp_ctx *espintcp_getctx(const struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + /* RCU is only needed for diag */ + return (__force void *)icsk->icsk_ulp_data; +} +#endif -- cgit v1.3.1