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, 48 insertions, 0 deletions

diff --git a/fs/ntfs/Kconfig b/fs/ntfs/Kconfig
new file mode 100644
index 000000000..6a6acde9b
--- /dev/null
+++ b/fs/ntfs/Kconfig
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTFS_FS
+	tristate "NTFS file system support"
+	select NLS
+	select FS_IOMAP
+	help
+	  NTFS is the file system of Microsoft Windows NT, 2000, XP and 2003.
+	  This allows you to mount devices formatted with the ntfs file system.
+
+	  To compile this as a module, choose M here: the module will be called
+	  ntfs.
+
+config NTFS_DEBUG
+	bool "NTFS debugging support"
+	depends on NTFS_FS
+	help
+	  If you are experiencing any problems with the NTFS file system, say
+	  Y here.  This will result in additional consistency checks to be
+	  performed by the driver as well as additional debugging messages to
+	  be written to the system log.  Note that debugging messages are
+	  disabled by default.  To enable them, supply the option debug_msgs=1
+	  at the kernel command line when booting the kernel or as an option
+	  to insmod when loading the ntfs module.  Once the driver is active,
+	  you can enable debugging messages by doing (as root):
+	  echo 1 > /proc/sys/fs/ntfs-debug
+	  Replacing the "1" with "0" would disable debug messages.
+
+	  If you leave debugging messages disabled, this results in little
+	  overhead, but enabling debug messages results in very significant
+	  slowdown of the system.
+
+	  When reporting bugs, please try to have available a full dump of
+	  debugging messages while the misbehaviour was occurring.
+
+config NTFS_FS_POSIX_ACL
+	bool "NTFS POSIX Access Control Lists"
+	depends on NTFS_FS
+	select FS_POSIX_ACL
+	help
+	  POSIX Access Control Lists (ACLs) support additional access rights
+	  for users and groups beyond the standard owner/group/world scheme.
+
+	  This option enables ACL support for ntfs, providing functional parity
+	  with ntfs3 drivier.
+
+	  NOTE: this is linux only feature. Windows will ignore these ACLs.
+
+	  If you don't know what Access Control Lists are, say N.