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, 54 insertions, 0 deletions

diff --git a/fs/cramfs/Kconfig b/fs/cramfs/Kconfig
new file mode 100644
index 000000000..4612c9bbf
--- /dev/null
+++ b/fs/cramfs/Kconfig
@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CRAMFS
+	tristate "Compressed ROM file system support (cramfs)"
+	select ZLIB_INFLATE
+	help
+	  Saying Y here includes support for CramFs (Compressed ROM File
+	  System).  CramFs is designed to be a simple, small, and compressed
+	  file system for ROM based embedded systems.  CramFs is read-only,
+	  limited to 256MB file systems (with 16MB files), and doesn't support
+	  16/32 bits uid/gid, hard links and timestamps.
+
+	  See <file:Documentation/filesystems/cramfs.rst> and
+	  <file:fs/cramfs/README> for further information.
+
+	  To compile this as a module, choose M here: the module will be called
+	  cramfs.  Note that the root file system (the one containing the
+	  directory /) cannot be compiled as a module.
+
+	  This filesystem is limited in capabilities and performance on
+	  purpose to remain small and low on RAM usage. It is most suitable
+	  for small embedded systems. If you have ample RAM to spare, you may
+	  consider a more capable compressed filesystem such as SquashFS
+	  which is much better in terms of performance and features.
+
+	  If unsure, say N.
+
+config CRAMFS_BLOCKDEV
+	bool "Support CramFs image over a regular block device" if EXPERT
+	depends on CRAMFS && BLOCK
+	default y
+	help
+	  This option allows the CramFs driver to load data from a regular
+	  block device such a disk partition or a ramdisk.
+
+config CRAMFS_MTD
+	bool "Support CramFs image directly mapped in physical memory"
+	depends on CRAMFS && CRAMFS <= MTD
+	default y if !CRAMFS_BLOCKDEV
+	help
+	  This option allows the CramFs driver to load data directly from
+	  a linear addressed memory range (usually non-volatile memory
+	  like flash) instead of going through the block device layer.
+	  This saves some memory since no intermediate buffering is
+	  necessary.
+
+	  The location of the CramFs image is determined by a
+	  MTD device capable of direct memory mapping e.g. from
+	  the 'physmap' map driver or a resulting MTD partition.
+	  For example, this would mount the cramfs image stored in
+	  the MTD partition named "xip_fs" on the /mnt mountpoint:
+
+	  mount -t cramfs mtd:xip_fs /mnt
+
+	  If unsure, say N.