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/esp.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 include/net/esp.h (limited to 'include/net/esp.h') diff --git a/include/net/esp.h b/include/net/esp.h new file mode 100644 index 000000000..322950727 --- /dev/null +++ b/include/net/esp.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_ESP_H +#define _NET_ESP_H + +#include + +struct ip_esp_hdr; +struct xfrm_state; + +static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb) +{ + return (struct ip_esp_hdr *)skb_transport_header(skb); +} + +static inline void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) +{ + /* Fill padding... */ + if (tfclen) { + memset(tail, 0, tfclen); + tail += tfclen; + } + do { + int i; + for (i = 0; i < plen - 2; i++) + tail[i] = i + 1; + } while (0); + tail[plen - 2] = plen - 2; + tail[plen - 1] = proto; +} + +struct esp_info { + struct ip_esp_hdr *esph; + __be64 seqno; + int tfclen; + int tailen; + int plen; + int clen; + int len; + int nfrags; + __u8 proto; + bool inplace; +}; + +int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp_input_done2(struct sk_buff *skb, int err); +int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp); +int esp6_input_done2(struct sk_buff *skb, int err); +#endif -- cgit v1.3.1