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, 62 insertions, 0 deletions

diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h
new file mode 100644
index 000000000..20ab344ba
--- /dev/null
+++ b/fs/afs/afs_fs.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* AFS File Service definitions
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef AFS_FS_H
+#define AFS_FS_H
+
+#define AFS_FS_PORT		7000	/* AFS file server port */
+#define FS_SERVICE		1	/* AFS File Service ID */
+
+enum AFS_FS_Operations {
+	FSFETCHDATA		= 130,	/* AFS Fetch file data */
+	FSFETCHACL		= 131,	/* AFS Fetch file ACL */
+	FSFETCHSTATUS		= 132,	/* AFS Fetch file status */
+	FSSTOREDATA		= 133,	/* AFS Store file data */
+	FSSTOREACL		= 134,	/* AFS Store file ACL */
+	FSSTORESTATUS		= 135,	/* AFS Store file status */
+	FSREMOVEFILE		= 136,	/* AFS Remove a file */
+	FSCREATEFILE		= 137,	/* AFS Create a file */
+	FSRENAME		= 138,	/* AFS Rename or move a file or directory */
+	FSSYMLINK		= 139,	/* AFS Create a symbolic link */
+	FSLINK			= 140,	/* AFS Create a hard link */
+	FSMAKEDIR		= 141,	/* AFS Create a directory */
+	FSREMOVEDIR		= 142,	/* AFS Remove a directory */
+	FSGIVEUPCALLBACKS	= 147,	/* AFS Discard callback promises */
+	FSGETVOLUMEINFO		= 148,	/* AFS Get information about a volume */
+	FSGETVOLUMESTATUS	= 149,	/* AFS Get volume status information */
+	FSGETROOTVOLUME		= 151,	/* AFS Get root volume name */
+	FSBULKSTATUS		= 155,	/* AFS Fetch multiple file statuses */
+	FSSETLOCK		= 156,	/* AFS Request a file lock */
+	FSEXTENDLOCK		= 157,	/* AFS Extend a file lock */
+	FSRELEASELOCK		= 158,	/* AFS Release a file lock */
+	FSLOOKUP		= 161,	/* AFS lookup file in directory */
+	FSINLINEBULKSTATUS	= 65536, /* AFS Fetch multiple file statuses with inline errors */
+	FSFETCHDATA64		= 65537, /* AFS Fetch file data */
+	FSSTOREDATA64		= 65538, /* AFS Store file data */
+	FSGIVEUPALLCALLBACKS	= 65539, /* AFS Give up all outstanding callbacks on a server */
+	FSGETCAPABILITIES	= 65540, /* Probe and get the capabilities of a fileserver */
+};
+
+enum AFS_FS_Errors {
+	VRESTARTING	= -100,	/* Server is restarting */
+	VSALVAGE	= 101,	/* volume needs salvaging */
+	VNOVNODE	= 102,	/* no such file/dir (vnode) */
+	VNOVOL		= 103,	/* no such volume or volume unavailable */
+	VVOLEXISTS	= 104,	/* volume name already exists */
+	VNOSERVICE	= 105,	/* volume not currently in service */
+	VOFFLINE	= 106,	/* volume is currently offline (more info available [VVL-spec]) */
+	VONLINE		= 107,	/* volume is already online */
+	VDISKFULL	= 108,	/* disk partition is full */
+	VOVERQUOTA	= 109,	/* volume's maximum quota exceeded */
+	VBUSY		= 110,	/* volume is temporarily unavailable */
+	VMOVED		= 111,	/* volume moved to new server - ask this FS where */
+	VIO		= 112,	/* I/O error in volume */
+	VSALVAGING	= 113,	/* Volume is being salvaged */
+	VRESTRICTED	= 120,	/* Volume is restricted from using  */
+};
+
+#endif /* AFS_FS_H */