bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/fs/befs/Kconfig b/fs/befs/Kconfig
new file mode 100644
index 000000000..5fcfc4024
--- /dev/null
+++ b/fs/befs/Kconfig
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config BEFS_FS
+	tristate "BeOS file system (BeFS) support (read only)"
+	depends on BLOCK
+	select BUFFER_HEAD
+	select NLS
+	help
+	  The BeOS File System (BeFS) is the native file system of Be, Inc's
+	  BeOS. Notable features include support for arbitrary attributes
+	  on files and directories, and database-like indices on selected
+	  attributes. (Also note that this driver doesn't make those features
+	  available at this time). It is a 64 bit filesystem, so it supports
+	  extremely large volumes and files.
+
+	  If you use this filesystem, you should also say Y to at least one
+	  of the NLS (native language support) options below.
+
+	  If you don't know what this is about, say N.
+
+	  To compile this as a module, choose M here: the module will be
+	  called befs.
+
+config BEFS_DEBUG
+	bool "Debug BeFS"
+	depends on BEFS_FS
+	help
+	  If you say Y here, you can use the 'debug' mount option to enable
+	  debugging output from the driver.