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, 119 insertions, 0 deletions

diff --git a/include/scsi/fcoe_sysfs.h b/include/scsi/fcoe_sysfs.h
new file mode 100644
index 000000000..2b28a05e4
--- /dev/null
+++ b/include/scsi/fcoe_sysfs.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2011-2012 Intel Corporation.  All rights reserved.
+ *
+ * Maintained at www.Open-FCoE.org
+ */
+
+#ifndef FCOE_SYSFS
+#define FCOE_SYSFS
+
+#include <linux/if_ether.h>
+#include <linux/device.h>
+#include <scsi/fc/fc_fcoe.h>
+
+struct fcoe_ctlr_device;
+struct fcoe_fcf_device;
+
+struct fcoe_sysfs_function_template {
+	void (*get_fcoe_ctlr_link_fail)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_ctlr_vlink_fail)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_ctlr_miss_fka)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_ctlr_symb_err)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_ctlr_err_block)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_ctlr_fcs_error)(struct fcoe_ctlr_device *);
+	void (*set_fcoe_ctlr_mode)(struct fcoe_ctlr_device *);
+	int  (*set_fcoe_ctlr_enabled)(struct fcoe_ctlr_device *);
+	void (*get_fcoe_fcf_selected)(struct fcoe_fcf_device *);
+	void (*get_fcoe_fcf_vlan_id)(struct fcoe_fcf_device *);
+};
+
+#define dev_to_ctlr(d)					\
+	container_of((d), struct fcoe_ctlr_device, dev)
+
+enum fip_conn_type {
+	FIP_CONN_TYPE_UNKNOWN,
+	FIP_CONN_TYPE_FABRIC,
+	FIP_CONN_TYPE_VN2VN,
+};
+
+enum ctlr_enabled_state {
+	FCOE_CTLR_ENABLED,
+	FCOE_CTLR_DISABLED,
+	FCOE_CTLR_UNUSED,
+};
+
+struct fcoe_ctlr_device {
+	u32				id;
+
+	struct device			dev;
+	struct fcoe_sysfs_function_template *f;
+
+	struct list_head		fcfs;
+	struct workqueue_struct		*work_q;
+	struct workqueue_struct		*devloss_work_q;
+	struct mutex			lock;
+
+	int                             fcf_dev_loss_tmo;
+	enum fip_conn_type              mode;
+
+	enum ctlr_enabled_state         enabled;
+
+	/* expected in host order for displaying */
+	struct fcoe_fc_els_lesb         lesb;
+};
+
+static inline void *fcoe_ctlr_device_priv(const struct fcoe_ctlr_device *ctlr)
+{
+	return (void *)(ctlr + 1);
+}
+
+/* fcf states */
+enum fcf_state {
+	FCOE_FCF_STATE_UNKNOWN,
+	FCOE_FCF_STATE_DISCONNECTED,
+	FCOE_FCF_STATE_CONNECTED,
+	FCOE_FCF_STATE_DELETED,
+};
+
+struct fcoe_fcf_device {
+	u32		    id;
+	struct device	    dev;
+	struct list_head    peers;
+	struct work_struct  delete_work;
+	struct delayed_work dev_loss_work;
+	u32		    dev_loss_tmo;
+	void                *priv;
+	enum fcf_state      state;
+
+	u64                 fabric_name;
+	u64                 switch_name;
+	u32                 fc_map;
+	u16                 vfid;
+	u8                  mac[ETH_ALEN];
+	u8                  priority;
+	u32                 fka_period;
+	u8                  selected;
+	u16                 vlan_id;
+};
+
+#define dev_to_fcf(d)					\
+	container_of((d), struct fcoe_fcf_device, dev)
+/* parentage should never be missing */
+#define fcoe_fcf_dev_to_ctlr_dev(x)		\
+	dev_to_ctlr((x)->dev.parent)
+#define fcoe_fcf_device_priv(x)			\
+	((x)->priv)
+
+struct fcoe_ctlr_device *fcoe_ctlr_device_add(struct device *parent,
+			    struct fcoe_sysfs_function_template *f,
+			    int priv_size);
+void fcoe_ctlr_device_delete(struct fcoe_ctlr_device *);
+struct fcoe_fcf_device *fcoe_fcf_device_add(struct fcoe_ctlr_device *,
+					    struct fcoe_fcf_device *);
+void fcoe_fcf_device_delete(struct fcoe_fcf_device *);
+
+int __init fcoe_sysfs_setup(void);
+void __exit fcoe_sysfs_teardown(void);
+
+#endif /* FCOE_SYSFS */