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, 101 insertions, 0 deletions

diff --git a/drivers/nfc/s3fwrn5/firmware.h b/drivers/nfc/s3fwrn5/firmware.h
new file mode 100644
index 000000000..19f479aa6
--- /dev/null
+++ b/drivers/nfc/s3fwrn5/firmware.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * NCI based driver for Samsung S3FWRN5 NFC chip
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Robert Baldyga <r.baldyga@samsung.com>
+ */
+
+#ifndef __LOCAL_S3FWRN5_FIRMWARE_H_
+#define __LOCAL_S3FWRN5_FIRMWARE_H_
+
+/* FW Message Types */
+#define S3FWRN5_FW_MSG_CMD			0x00
+#define S3FWRN5_FW_MSG_RSP			0x01
+#define S3FWRN5_FW_MSG_DATA			0x02
+
+/* FW Return Codes */
+#define S3FWRN5_FW_RET_SUCCESS			0x00
+#define S3FWRN5_FW_RET_MESSAGE_TYPE_INVALID	0x01
+#define S3FWRN5_FW_RET_COMMAND_INVALID		0x02
+#define S3FWRN5_FW_RET_PAGE_DATA_OVERFLOW	0x03
+#define S3FWRN5_FW_RET_SECT_DATA_OVERFLOW	0x04
+#define S3FWRN5_FW_RET_AUTHENTICATION_FAIL	0x05
+#define S3FWRN5_FW_RET_FLASH_OPERATION_FAIL	0x06
+#define S3FWRN5_FW_RET_ADDRESS_OUT_OF_RANGE	0x07
+#define S3FWRN5_FW_RET_PARAMETER_INVALID	0x08
+
+/* ---- FW Packet structures ---- */
+#define S3FWRN5_FW_HDR_SIZE 4
+
+struct s3fwrn5_fw_header {
+	__u8 type;
+	__u8 code;
+	__u16 len;
+};
+
+#define S3FWRN5_FW_CMD_RESET			0x00
+
+#define S3FWRN5_FW_CMD_GET_BOOTINFO		0x01
+
+struct s3fwrn5_fw_cmd_get_bootinfo_rsp {
+	__u8 hw_version[4];
+	__u16 sector_size;
+	__u16 page_size;
+	__u16 frame_max_size;
+	__u16 hw_buffer_size;
+};
+
+#define S3FWRN5_FW_CMD_ENTER_UPDATE_MODE	0x02
+
+struct s3fwrn5_fw_cmd_enter_updatemode {
+	__u16 hashcode_size;
+	__u16 signature_size;
+};
+
+#define S3FWRN5_FW_CMD_UPDATE_SECTOR		0x04
+
+struct s3fwrn5_fw_cmd_update_sector {
+	__u32 base_address;
+};
+
+#define S3FWRN5_FW_CMD_COMPLETE_UPDATE_MODE	0x05
+
+struct s3fwrn5_fw_image {
+	const struct firmware *fw;
+
+	char date[13];
+	u32 version;
+	const void *sig;
+	u32 sig_size;
+	const void *image;
+	u32 image_sectors;
+	const void *custom_sig;
+	u32 custom_sig_size;
+};
+
+struct s3fwrn5_fw_info {
+	struct nci_dev *ndev;
+	struct s3fwrn5_fw_image fw;
+	char fw_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
+
+	const void *sig;
+	u32 sig_size;
+	u32 sector_size;
+	u32 base_addr;
+
+	struct completion completion;
+	struct sk_buff *rsp;
+	char parity;
+};
+
+int s3fwrn5_fw_request_firmware(struct s3fwrn5_fw_info *fw_info);
+void s3fwrn5_fw_init(struct s3fwrn5_fw_info *fw_info, const char *fw_name);
+int s3fwrn5_fw_setup(struct s3fwrn5_fw_info *fw_info);
+bool s3fwrn5_fw_check_version(const struct s3fwrn5_fw_info *fw_info, u32 version);
+int s3fwrn5_fw_download(struct s3fwrn5_fw_info *fw_info);
+void s3fwrn5_fw_cleanup(struct s3fwrn5_fw_info *fw_info);
+
+int s3fwrn5_fw_recv_frame(struct nci_dev *ndev, struct sk_buff *skb);
+
+#endif /* __LOCAL_S3FWRN5_FIRMWARE_H_ */