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/x25device.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 include/net/x25device.h (limited to 'include/net/x25device.h') diff --git a/include/net/x25device.h b/include/net/x25device.h new file mode 100644 index 000000000..cf749efca --- /dev/null +++ b/include/net/x25device.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _X25DEVICE_H +#define _X25DEVICE_H + +#include +#include +#include +#include + +static inline __be16 x25_type_trans(struct sk_buff *skb, struct net_device *dev) +{ + skb->dev = dev; + skb_reset_mac_header(skb); + skb->pkt_type = PACKET_HOST; + + return htons(ETH_P_X25); +} +#endif -- cgit v1.3.1