selftests/bpf: Reject graph kptr use after RCU unlockgrafted

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 <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 159 insertions, 0 deletions

diff --git a/drivers/scsi/fnic/fip.h b/drivers/scsi/fnic/fip.h
new file mode 100644
index 000000000..79fee7628
--- /dev/null
+++ b/drivers/scsi/fnic/fip.h
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2008 Cisco Systems, Inc.  All rights reserved.
+ * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
+ */
+#ifndef _FIP_H_
+#define _FIP_H_
+
+#include "fdls_fc.h"
+#include "fnic_fdls.h"
+#include <scsi/fc/fc_fip.h>
+
+/* Drop the cast from the standard definition */
+#define FCOE_ALL_FCFS_MAC {0x01, 0x10, 0x18, 0x01, 0x00, 0x02}
+#define FCOE_MAX_SIZE 0x082E
+
+#define FCOE_CTLR_FIPVLAN_TOV (3*1000)
+#define FCOE_CTLR_FCS_TOV     (3*1000)
+#define FCOE_CTLR_MAX_SOL      (5*1000)
+
+#define FIP_DISC_SOL_LEN (6)
+#define FIP_VLAN_REQ_LEN (2)
+#define FIP_ENODE_KA_LEN (2)
+#define FIP_VN_KA_LEN (7)
+#define FIP_FLOGI_LEN (38)
+
+enum fdls_vlan_state {
+	FIP_VLAN_AVAIL,
+	FIP_VLAN_SENT
+};
+
+enum fdls_fip_state {
+	FDLS_FIP_INIT,
+	FDLS_FIP_VLAN_DISCOVERY_STARTED,
+	FDLS_FIP_FCF_DISCOVERY_STARTED,
+	FDLS_FIP_FLOGI_STARTED,
+	FDLS_FIP_FLOGI_COMPLETE,
+};
+
+/*
+ * VLAN entry.
+ */
+struct fcoe_vlan {
+	struct list_head list;
+	uint16_t vid;		/* vlan ID */
+	uint16_t sol_count;	/* no. of sols sent */
+	uint16_t state;		/* state */
+};
+
+struct fip_vlan_req {
+	struct ethhdr eth;
+	struct fip_header fip;
+	struct fip_mac_desc mac_desc;
+} __packed;
+
+struct fip_vlan_notif {
+	struct fip_header fip;
+	struct fip_vlan_desc vlans_desc[];
+} __packed;
+
+struct fip_vn_port_ka {
+	struct ethhdr eth;
+	struct fip_header fip;
+	struct fip_mac_desc mac_desc;
+	struct fip_vn_desc vn_port_desc;
+} __packed;
+
+struct fip_enode_ka {
+	struct ethhdr eth;
+	struct fip_header fip;
+	struct fip_mac_desc mac_desc;
+} __packed;
+
+struct fip_cvl {
+	struct fip_header fip;
+	struct fip_mac_desc fcf_mac_desc;
+	struct fip_wwn_desc name_desc;
+	struct fip_vn_desc vn_ports_desc[];
+} __packed;
+
+struct fip_flogi_desc {
+	struct fip_desc fd_desc;
+	uint16_t rsvd;
+	struct fc_std_flogi flogi;
+} __packed;
+
+struct fip_flogi_rsp_desc {
+	struct fip_desc fd_desc;
+	uint16_t rsvd;
+	struct fc_std_flogi flogi;
+} __packed;
+
+struct fip_flogi {
+	struct ethhdr eth;
+	struct fip_header fip;
+	struct fip_flogi_desc flogi_desc;
+	struct fip_mac_desc mac_desc;
+} __packed;
+
+struct fip_flogi_rsp {
+	struct fip_header fip;
+	struct fip_flogi_rsp_desc rsp_desc;
+	struct fip_mac_desc mac_desc;
+} __packed;
+
+struct fip_discovery {
+	struct ethhdr eth;
+	struct fip_header fip;
+	struct fip_mac_desc mac_desc;
+	struct fip_wwn_desc name_desc;
+	struct fip_size_desc fcoe_desc;
+} __packed;
+
+struct fip_disc_adv {
+	struct fip_header fip;
+	struct fip_pri_desc prio_desc;
+	struct fip_mac_desc mac_desc;
+	struct fip_wwn_desc name_desc;
+	struct fip_fab_desc fabric_desc;
+	struct fip_fka_desc fka_adv_desc;
+} __packed;
+
+void fnic_fcoe_process_vlan_resp(struct fnic *fnic, struct fip_header *fiph);
+void fnic_fcoe_fip_discovery_resp(struct fnic *fnic, struct fip_header *fiph);
+void fnic_fcoe_process_flogi_resp(struct fnic *fnic, struct fip_header *fiph);
+void fnic_work_on_fip_timer(struct work_struct *work);
+void fnic_work_on_fcs_ka_timer(struct work_struct *work);
+void fnic_fcoe_send_vlan_req(struct fnic *fnic);
+void fnic_fcoe_start_fcf_discovery(struct fnic *fnic);
+void fnic_fcoe_start_flogi(struct fnic *fnic);
+void fnic_fcoe_process_cvl(struct fnic *fnic, struct fip_header *fiph);
+void fnic_vlan_discovery_timeout(struct fnic *fnic);
+
+extern struct workqueue_struct *fnic_fip_queue;
+
+#ifdef FNIC_DEBUG
+static inline void
+fnic_debug_dump_fip_frame(struct fnic *fnic, struct ethhdr *eth,
+				int len, char *pfx)
+{
+	struct fip_header *fiph = (struct fip_header *)(eth + 1);
+	u16 op = be16_to_cpu(fiph->fip_op);
+	u8 sub = fiph->fip_subcode;
+
+	FNIC_FCS_DBG(KERN_DEBUG, fnic->host, fnic->fnic_num,
+		"FIP %s packet contents: op: 0x%x sub: 0x%x (len = %d)",
+		pfx, op, sub, len);
+
+	fnic_debug_dump(fnic, (uint8_t *)eth, len);
+}
+
+#else /* FNIC_DEBUG */
+
+static inline void
+fnic_debug_dump_fip_frame(struct fnic *fnic, struct ethhdr *eth,
+				int len, char *pfx) {}
+#endif /* FNIC_DEBUG */
+
+#endif	/* _FIP_H_ */