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, 69 insertions, 0 deletions

diff --git a/fs/smb/common/smbglob.h b/fs/smb/common/smbglob.h
new file mode 100644
index 000000000..4e33d91cd
--- /dev/null
+++ b/fs/smb/common/smbglob.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: LGPL-2.1 */
+/*
+ *
+ *   Copyright (C) International Business Machines  Corp., 2002,2008
+ *                 2018 Samsung Electronics Co., Ltd.
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *              Jeremy Allison (jra@samba.org)
+ *              Namjae Jeon (linkinjeon@kernel.org)
+ *
+ */
+#ifndef _COMMON_SMB_GLOB_H
+#define _COMMON_SMB_GLOB_H
+
+struct smb_version_values {
+	char		*version_string;
+	__u16		protocol_id;
+	__le16		lock_cmd;
+	__u32		req_capabilities;
+	__u32		max_read_size;
+	__u32		max_write_size;
+	__u32		max_trans_size;
+	__u32		max_credits;
+	__u32		large_lock_type;
+	__u32		exclusive_lock_type;
+	__u32		shared_lock_type;
+	__u32		unlock_lock_type;
+	size_t		header_size;
+	size_t		max_header_size;
+	size_t		read_rsp_size;
+	unsigned int	cap_unix;
+	unsigned int	cap_nt_find;
+	unsigned int	cap_large_files;
+	unsigned int	cap_unicode;
+	__u16		signing_enabled;
+	__u16		signing_required;
+	size_t		create_lease_size;
+	size_t		create_durable_size;
+	size_t		create_durable_v2_size;
+	size_t		create_mxac_size;
+	size_t		create_disk_id_size;
+	size_t		create_posix_size;
+};
+
+static inline unsigned int get_rfc1002_len(void *buf)
+{
+	return be32_to_cpu(*((__be32 *)buf)) & 0xffffff;
+}
+
+static inline void inc_rfc1001_len(void *buf, int count)
+{
+	be32_add_cpu((__be32 *)buf, count);
+}
+
+#define SMB1_VERSION_STRING	"1.0"
+#define SMB20_VERSION_STRING    "2.0"
+#define SMB21_VERSION_STRING	"2.1"
+#define SMBDEFAULT_VERSION_STRING "default"
+#define SMB3ANY_VERSION_STRING "3"
+#define SMB30_VERSION_STRING	"3.0"
+#define SMB302_VERSION_STRING	"3.02"
+#define ALT_SMB302_VERSION_STRING "3.0.2"
+#define SMB311_VERSION_STRING	"3.1.1"
+#define ALT_SMB311_VERSION_STRING "3.11"
+
+#define CIFS_DEFAULT_IOSIZE (1024 * 1024)
+
+#define MAX_CIFS_SMALL_BUFFER_SIZE 448 /* big enough for most */
+
+#endif	/* _COMMON_SMB_GLOB_H */